How to Read and Open .DAT Files in Windows

So you just received an email with an attachment that someone sent you, but the extension on the file is .DAT. What exactly is a .DAT file and how to you open .DAT files? Those are two questions I’m going to try to answer as this is an issue that I’ve seen many times in my IT career!

The first thing to understand about .DAT files is that it indicates a file that has arbitrary data. That means it’s not associated with any one particular program or application. When you see a file with a .XLS extension, you know it’s referring to an Excel file, and so on. But with .DAT files, you have to figure out how to open it yourself and it may not be the same program each time.

file types

The best way to open a .DAT file is to use the program that created it. However, if you’re not sure, you can always try Notepad. Now when you open it in Notepad, you may be able to recognize some of the data, but the rest will most likely be junk spewed out by the program that created it.

You’ll normally only see this file format when receiving emails with attachments. Most common programs today do not generate .DAT files and only computer programmers use these files on any kind of regular basis.

So your first step would be to ask the person who sent you the email if they know which program was used to create the file. Now if they tell you that they actually sent a picture or a document and they are not sure why it’s a .DAT file, it could be that the file extension was changed in the process of having the email routed to you.

For some strange reason, some email programs automatically change the file extension on email attachments to .DAT. So if the person sent you a picture and now it’s a .DAT file, you first need to save it to your computer and then change the file extension to JPG or GIF or PNG or whatever you think it’s supposed to be. If they sent you a Word document, change it to .DOC, etc.

You can change the file extension on a file by first going to My Computer, clicking on Tools and then Folder Options.

tool folder options

Next click on the View tab and then scroll down to the option “Hide extensions for known file types” and UNCHECK it. In this way, we’ll now be able to see the file extension and change it to something else.

hide file extension

Now simply right-click on the .DAT file and change the file extension after the dot to the desired file format.

change file extension

You should also see the icon representing the file change to the appropriate program use to open that file type, i.e. Excel in the above picture.

So what do you do if you’re not sure which program it came from or what the original file extension was supposed to be? You can also try right-clicking on the file and then choosing Open With and try different programs. For example, I changed one of my Excel files to a .DAT extension and then right-clicked on it to open it with Excel and it worked!

open .dat file

Now I just chose Microsoft Excel from the list and Excel was able to read the file since the data was written by Excel, it just had a wrong file extension.

open file

You can also try other programs like Windows Media Player since it will open it if it happens to be a video, MP3, or similar media format. So hopefully you are now able to open your mysterious .DAT file using one of the above mentioned methods! If not, post a comment and I will try to help! Enjoy!

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  1. Madhur Kapoor says:

    I always thought that DAT files were for Videos . My doubts are cleared.

  2. akishore says:

    Hey Madhur,

    .DAT files can be video files and are a lot of times, but the format itself is for "arbitrary" data. Emails programs have a tendency to change the file extension to .DAT.

  3. lorraine says:

    my .dat file is a video file but can't open with windows media player and realplayer. please advise any other software allows me to watch this video file.

  4. Julie says:

    Opening the file is not the problem. I can't figure out what program it was created in and have tried everything–all the instructions say use notepad–doens't work!!

  5. akishore says:

    Julie, who did you get the file from? If you have any slight idea what the DAT file could have been generated from, then just try to rename the extension and see if it opens. I would try .XLS, .DOC, .AVI, .PNG, .JPG, etc etc. It's got to be a common extension.

  6. zoheb says:

    You're the man!! This post was a great help….I was breaking my head in trying to download corel from the Internet because I thought it was a file made in corel, but after reading your post I just changed the extension to .jpeg and presto I get my file..thanks buddy for your efforts !!

  7. Galzaga says:

    I have a site with videos i surf often but it doesn’t allow you to download the “supposed” wmv files. Now, I play the videos in IE, then I go to settings and view files and the file is there, and of course is a video file around 20 mb. The name of the file is usually something like this: video1.wmv#0;000;0;0;1:2;2:2. What I do is to copy that file and paste it on the desktop and I get a file with a different name, usually something like: video1[1].dat.

    I tried all different kind of codecs, video inspectors, different video programs and no success. There is no way to open those files, I hope somebody can help. Thanks.

  8. James Slattery says:

    Many thanks for your ideas on identifying a .dat file. Without your prompts I would not have been able to open the file.

  9. Linda Derwick says:

    my dat file came from a mac–applefile supposedly as a compatible word file–I used your suggestion and changed file extension to doc but still can't read it in word. Does anyone have any suggestions?

  10. Tammy Storrs says:

    I did a search on Google for how to open DAT files, and your answer is the best I have found.

    thank you,

  11. cyndi says:

    HELP! I got a dat file and I can't seem to open it at all. it came through in winmail.dat

  12. Shirley says:

    I am having a problem… using PSPX2..when I save and send an image its being received as DAT file yet I saved and sent it as a JPG file …must be a setting that is incorrect but cannot find it…

    thanks for any help

  13. Sandra says:


    Good Afternoon..

    First thank you for your detailed

    instructions regarding how to Open

    up a .Dat file in Windows XP Prof.

    Well, I went to My Computer, Tools

    Folder Options, View and UNCHECKED

    the Hidden files..

    Then went back and Rt clicked on

    the .Dat file..but still it will

    not allow me to do a thing..

    It says I can go to the Internet

    maybe in a List find something

    to assist me to Open this .Dat


    Must say, this is a tad confusing

    for me, as I am so NOT Technically

    inclined per say..

    So if you can suggest another way

    to Open the .dat file.

    I haven't tried Windows Media Player

    because it isn't Music, but a Knitting

    Pattern a friend sent me..??

    Thanks again.


  14. Ket says:

    I've tried to open the dat files for years and I couldn't open it. They're still well keeping on my computer and my next computer too.

    They are pictures that very important to me. It's my wedding photos.

    I shot them with the digital camera. The guest who participated the event try to impress us. He download them to my computer and make it viewable by PowerDVD. They just worked like a charm.

    We love it at first, but as he left, I don't know why, we cannot open it as he demonstrated.

    The pictures can still be viewed by PowerDVD but at very fast rate, less than a seconds per picture I guess, so we cannot actually view the photos.

    Since we cannot print them out, I just keep them safe on my computer.

    And now I am divorced, I really want to watch those photos again. I search high and low through google and run into your site.

    I would be very very appreciated if you can help me.


  15. L White says:

    I am experiencing the same problem Cyndi is. I also received an e-mail with a winmail.dat attachement. I followed the steps and tried renaming the file so I can open it, but no luck. I just sent an e-mail to the person who sent me the attachement to ask which program was used to create the program. This wesbite was very helpful and Akishore, although I was unable to open my attachment the information you provided was very helpful and informational. You didn't have to create this site, but you did and it is appreciated.

  16. L White says:

    I stumbled onto this website and was able to open the attachment winmail.dat. Hope this helps everyone else.

  17. jefu says:

    this site was very helpful. although i wasnt able open my winmail.dat file, i did learned something from here.. i tried following the solutions you provided but it didnt work. ill just have to ask my customer to ask the person who sent that file and ask him what kind of software he used to create that file.. thanks a lot..

  18. anm says:

    Hi… How do you open .dat files that are archived conversation from Yahoo Messenger? i tried what u said but i didn't work.. will appreciate ur help.. tq

  19. Silver says:

    @ ket: chance the file extension of the file to .psz

    so instead of .dat you will have psz and will be able to open with powerdvd if im correct.

    @anm: try to open with .txt

    i hope this helps for you guys.

  20. Gaiyya says:

    actually i want to open one of my yahoo messenger archives! and its in this "Video CD Movie" format or whatever and it has the .dat format. and i open it using notepad but i get a lot of gibberish!! :S :( heeeeellllpppppppp!?

  21. Tom Tonks says:

    Try IrfanView. It will open many pictures and movies.

  22. Gigi says:

    Thank you. This is very helpful.

  23. KP says:

    downloading a setup.exe file from ITunes, saves as a .dat file and not an executable. If I change it to .exe, will i then perform the setup?

    Secondly, why would it download as a .dat as opposed to a .exe in the first place?

    Many thanks

  24. Sudhir Vardhan says:

    This information was simply great. It saved me a lot of hassle of finding out what kind of file it was. I was perplexed to see the .dat extension files in my email. the sender told me to open in the fax viewer. I was unable to open the same in Window Vista. Ultimately based upon your guidance stated above i inserted the extension .jpeg and behold!!!!! the file opened. BINGO!!! BINGO !!!

  25. jamil says:

    I have a dat file and i don’t know by which program it was created.Is there any way to open the file other than checking with different program

  26. Esteban says:

    Ecellent post man, I resolved this with that. Was simply amazing and easy *-* Jeje! *-* Thank you again!!

  27. Anthony says:

    I have a .dat file that is part of a program how can I open that file.

  28. Matt says:

    Ah well done.

    Changed the attachment extension to .jpg, and viewed the photos without a problem.

    Thanks for the excellent explanation too.

    Seems my service provider has an email server that strips off the extensions and replaces them with .dat for email attachments.


  29. drago says:


    I have a .dat file downloaded from a website to unlock my iphone but i just can't open it whit anything. it's a program but it doesn't want to open. can someone help me please. I'm from holland (netherlands)


  30. chen says:

    thanks for the info. i just want to know if there is a relation between DXF Files, SDNF files and DAT files?

    can you explain it to me please.

  31. Recker says:

    I'll say it again in English! Your advice was a great help and I'm really thankful, since I do receive files that I canb't open from time to time, and it was usually with a dat extension. My question was just if I should leave the box "Hide …." unchecked without any risk or if I should check it again. Thanks anyway, people like you are really godsent!

  32. Chate says:

    I have a .dat file but it isnt a text format it is from an unknown program.Is there a way i could find out which program it is?

  33. Garry says:

    Hi, I received a cd that had information copied to it from MYOB13 and when I place it in my laptop, it comes up as a dat file. My computer is Windows XP, I have read your article but I am still stumped (and frustrated)my partner's computer whom copied it for me, is Windows 98. Please help!

  34. natalie says:

    i restart my laptop everyday which has vista on it an i get a box pop up saying that qysmuim.exe has caused a problem an needs to close it came with 3 dat files also named qysmuim dont know where it came from… its in my userusernameappdatalocalmicrosoftqysmuim.exe did a search on the web to see what qysmuim was an found nothing.. needless to say the exe an the dat files wont open an i scaned for virus an there was now what? lol

  35. Wayne says:

    Thanks for the help. Just a side hint for everyone;

    At bare minimum, if you do open a DAT file in notepad or some other text editor – often you can read in the file header what the file type is and then what you can open it with.

    Good luck!!

  36. Joel says:

    I want to open .dat file. Let me know from which application it will get opened…since it is a file which has to be filled and sent to a company

    Let me know ASAP


  37. Lisa Love says:

    Thank you L White for your post in response to Cyndi's problem because I was experiencing the same issue, and even though this posting itself was very helpful I still needed more help. Your post, which I C&P here: "L White said on : August 16th, 2008 at 11:42 am

    I stumbled onto this website and was able to open the attachment winmail.dat. Hope this helps everyone else."

    with the link was my lifesaver. Thank you so much for sharing. Hope this helps a lot of other people, too.
    Happy Holidays!! (^_^)

  38. shravanti says:

    gr8 post… it was really helpfull

  39. jignesh says:

    Thanks very much. After changing DAT extension to pdf i can open file with adobe acrobat.

  40. Ronald says:

    I have a .dat file and still can't open it. Tried renaming to .doc -NO PRIZE! Tried opening with notepad, excel, access – NO PRIZE! I tried your directions, nothing works. Any ideas?

  41. BRUCE says:

    I have dat files created with a multitrac recording studio, the mrs1044cd by ZOOM. I copied the audio files usb02 to a folder/desktop, and although I can play them on the zoom hardware I would like to have copies on my harddrive. any tips would be cool. Bruce

  42. sekhar says:

    I got wonderful answer to my problem. Actually I have a .dat file and still can’t open it. After reading the artcile from ur website, i opened it.

    Thank u very much

  43. Summer says:

    I went to burn a video disc through Nero and somehow it has changed it into a dat file. I have tried everything and I am getting really frustrated. It will be 2 years in May, and am still trying to open it. I have my son's birthday and my niece's 21st birthday on there. Please help!!!

  44. Jorge says:

    After following your step by step instructions and applying the change in MY Computer.

    I went to the folder where I stored the .dat file , I right clicked and went to properties , there I replaced the .dat with .jpg and clicked on Change….

    It worked like a charm , my .dat file was now .jpg and the picture was viewable , Thank You for the information.

  45. Ben says:

    I have a vista, if I clicked properties and saw "opens with:(program here)" what would that mean? Should I download the file or what?

  46. Ritesh says:

    Thanks Boss…thanks a ton…

  47. Aisha says:

    Hey this is a great and useful post however i amk still stuck and i wonder if you can help me. you see i downloaded some DAT files from the following site I clicked on the links to get them, they are images but they appear to be in DAT format, however, I cant seem to access them when using a PNG BMP or JPEG extension. Would you be able to help? ill be most grateful Thanks in advance.

  48. ken says:

    If you need to open .dat files from Yahoo Messenger try this link:

    It worked on my older YM archives from 2007

    Good Luck

  49. Dean says:


    SORRY caps.

  50. aytee says:

    You are my hero! THANKS

  51. Hany Nadim says:

    I always send excel files as mail attachments, but they receive it in .DAT extension. i do not know why it changes
    to a DAT file. i want the file to arrive in it's original format Excel. pls help

  52. Dilian says:

    I have an Icy Tower game MOD and the file format is .DAT, so how can I open it, which program must i use???

  53. Rider says:

    what you can try also is to open it with internet explorer, It worked for me (it was an image)

  54. Rita says:

    Dear friend,

    I have read your article cause I was searching a method to open my .dat file. Unfortunately this system does not work with me. I have converted this file in numerous extensions but nothing! Could you help me to solve this matter? It's important cause is a file for working!



  55. Sacha says:

    i emailed myself outlook contacts, but when i recieve them they appear as attachment of .dat files. i followed your instruction on changing it to approriate application (.vcf) but when it opens all the data on the contact card is missing! PLEASE HELP!!!

    not sure what i need to do to make the contact details appear with the card! :(

  56. Aina says:

    I can never open .dat files in my aol account, but when I forward the email to my yahoo account, I can open the files? Tried hotmail also, but it didn't work. For some reason yahoo is able to read the files?

  57. carroll says:

    I just received an email with the .dat file extension at my work email (I use thunderbird). Couldn't open it so I forwarded it to my gmail account and all the information came through no problem!

  58. Suzanne says:

    Your first few paragraphs saved me!! Someone sent me a huge excel spreadsheet that came through as a .dat file. Your feedback was perfect in explaining what a .dat file is, why a file might come through with that extension and how to change the settings that would allow me to change the extension. Once I did all that, no problema! It's never a lost day when I can say I learned something new! Thank you so much!

  59. Shevon says:

    I am trying to open a map that is an .at5 file, can you help? Thanks

  60. Aiv J. says:

    It's a nice post you have there. Solved a major problem.

  61. Shirl Smith says:

    I received .dat files on a CD. They were photos taken

    with a digital camera and I imagine were originaly

    .jpgs. I was told they were for the TV DVD player. That

    didn't work, but realplayer on my computer opens them.

    Not a perfect solution but can view them one at a time

    not as a slide show which I would have prefered.


  62. Mark says:

    For those of you with .dat video files you can't open, do a google search for VLC media player. It can open almost anything and it's free. I've been using it for years.


    url if you are to lazy to search. :)

  63. brenda says:

    I have a .dat file which shows up saying I should be able to open it using Adobe. It won't allow me to do that. Changing the file extension doesn't help. It just shows the file name as XXXX.pdf.dat and keeps trying to use Adobe to open it. When I changed the file extension to .gif or .bmp it still keeps the .dat also. HELP!

  64. Misty says:


    My .dat files are from yahoo messenger. I accidentally, dont know how, deleted my archives, so i had to go download a recover program and the messages came up as .dat files. i dont know how to open them, does anyone know how to help me? and how do i know that they are messages or what they are?

  65. Kang Rosil says:

    Save the files to your drive and rename it's extentention from dat to doc ( MS Words ). I tried it and success Thank's…

  66. Sunil Lal says:

    I tried all the tips. But I coudn't open the .DAT file. Could you please help me?

  67. Eyobee says:

    I also received .dat file on CD. Actually it's a movie recorded by a digital camera. But i couldn't it yet, even with real player. Would you please help with this problem. Thank you in Advance.


  68. kent says:

    What if the dat file is a folder? Can you still open it? How?

  69. kavita says:


    I have several files: .dat, .idx, .ibk, but this not any kind of video file. These are some database files. Can any one tell me how to open or see the content of these files?

  70. sylverbull says:

    Thanks your tutorial on how to change a .DAT file to the desired file, help me a lot and I just wanted to thank you. There are lots of stuff behind the computer one does not know ….wow!!! really technical but thank heavens I can follow instructions. Goooood one pal!

  71. sp says:

    I just saved the file to my desktop, renamed the extension to XLS and double-clicked on it to open. Worked fine!

  72. Thank you so much! I changed the file extension on an IMPOSSIBLE .DAT file and was able to open it on the first try in .PDF format. Now I can get my client invoice to him today as promised! You saved the weekend!

  73. Tim Mcdonald says:


    I've been trying to play a .dat file all day. Its from a VCD but the computer doesn't recognize it. I've tried open with media player too, but it says cannot play this file type… any more idea?

  74. Sue says:

    I want to uninstall a game but the only file in the 'uninstall' folder is a .dat file which I can't open. I don't want to keep the game in my com as it takes up a lot of space. Can you give me any advice?

  75. Jo C says:

    Thank You, Thank You, Thank You!! Your suggestions saved the day!

  76. Jim Hammond says:

    Thanks for the help! I'm putting a food & wine article to bed, but needed a chef's recipe to complete it and it arrived in .dat format. Used your info, guessed it was in .doc and was right. Submission done in time, phew!

  77. Fran says:

    I tried to open some archived messages from yahoo messenger that was sent in an email as an attachment.. tried changing from dat and will still not allow me to read. Any sugggestions?

  78. James says:

    Thanks for your help. This post was a great one. I can now open DAT files.

  79. Pat says:

    Thanks! A colleague had forwarded two files with ".dat" — interestingly, two others came through as ".doc".

    It turned out one was a .doc and one was .xls, and we were all able to view these files.

    Thanks again.


  80. concon says:

    Hi! I need my old chats but when i opened it, it is a DAT file and the icon is for my media player! I tried all kind of ways to covert it to txt, doc, xls. It is a messages archive from my past chats that I need to present to the US embassy of chats with my husband!! Pls help!!!!

  81. GwB says:

    Here's what I did. I downloaded a documentary consisting of a few WINRAR files. When I extracted these WINRAR files, it turned out to be a .DAT file which could not be recognized by Windows Media Player. Then I started VLC player and when opening the file I selected "All Files(*)" in "Files of Type". No problem whatsoever…

  82. Dee says:

    This is really helpful. My boss was impressed with me! :)

    Thanks a lot.


  83. siete uno says:

    hi! I just tried to change a .dat file to .txt, .doc, .excel, .mp3 and to any other known file types. unfortunately, none of them worked. :(

    what im actually tring to convert are the messages from my YM Archives. They are all in .dat form.

    I can open the files using Yahoo Messengers Archive but I am trying to convert them to word files so i can just create a 1 page document for the conversations that i had.

    Is it possible?

    Hope I made some sense in my query. :)

    Thank you,

    siete uno

  84. vish says:


    First of all thanks for such useful information. 'index.dat' file which gets created in 'Temporary Internet Files' folder contains the names and even the dates of your first visits to many pages. I tried to open it with different progs like notepad, wordpad, word, excel….but i am not able to read the content…if you find any solution, email me at ""


  85. Margaret Swank says:

    Help. A good friend sent lots of photos via email. I downloaded them, sent them to windows media player. When I tried viewing them, a message pops up to tell me; the selected files has a extension (.zip) that is not recognized by windows media player, but might still be able to open it, then I check that box,and get another message. In other words, it won't open it. I have windows vista.

  86. james says:

    try VLC player…

  87. Ananta C says:

    In our company we generate .dat files with inhouse application, I had fixed strange problem. I can open those .dat file in excel by browsing file –> open , but not when I double click ( after associating to open always open in excel ). below is solution

    open folder option —>file types — dat and click advanced button ( some times you may have restore button, click restore and you will get advanced )

    in advanced – select open — edit and paste the path of "x:….excel.exe" /e and click ok/apply

    eg : "C:Program FilesMicrosoft OfficeOffice12EXCEL.EXE" /e

    boom.. it should work

  88. Elizabeth says:

    Thanks very much for excellent explanation and solution. I changed the name to extension .jpg and could view and save the picture. Can it be caused by the person sending the attachment using plain text?

  89. Thanks for sharing and posting your article here. This one is a great help. I had no clue how to open a .DAT file.

  90. S Murthy says:

    I have been using Windows outlook 2007 after upgrading from 2003. Now all files that i send are converted to .DAT files. This is creating problems for my clients as I need to transfer various kinds of data at a time and cannot really specify the file type everytime. Is there some way to configure outlook to send mails as is without converting it. Thanks

  91. JIM says:

    I was sent a pdf file whcih converted to a dat file. I changed the file extension to pdf, but it would not open

  92. Ellie says:

    I exported my earthlink messages in folders to a flash drive in anticipation of setting up a new vista machine. The file is there as a .DAT and now I can't export it to the new machine. Any suggestions?

  93. Jeff says:


    my .dat file is a map related file.(map for GPS unit) which program should i use to open it?


  94. andrei says:

    hey, this post is great. I know a litle about this and here it goes:

    For video files even those pictures made for powerdvd should open with vlc and is really nice now(much improved.)

    For pictures you should try more endings: .jpg .jpeg .png .iff .tiff. it all depends where it came from. now days pictures from the internet come as png. if is a scan chances are it is an tiff or a ttf. normal pictures ussually store as jpg or jpeg, espeacially from everyday camera on the market. very few have specific attributes, I came across a jvc once with a jvp format but I think it only goes for the copycat's on the market (the really cheap chinese trickery products.)

    If it is from a game it is deffinetly in their own language and not sure at all if can be open by anything. if notepad doesn't see just blocks and squares then it is probably encripted.

    For messenger (yahoo) files u can go to and see what is around for decoding there are several programs there and most are free or free period trial. sa decode and don't forget to save in something else.

    For the rest I saw a lot of good answers. and usualy just changing the attribute should work (careful now cause docx is way different then doc, and so forth xls, and ppt). for the pictures slides u can try pps or ppt. even mp3 work like that some times. and most recent video format on the net is flv. I think this is about everything. hope it helps.

    So remember if u can't see it in notepad it is probably encrypted and very few programs can decrypt it directly (vlc, ie, irfanview for pics, and if I remember correctly PowerISO for cd images or magic iso).

    good luck!!!

  95. andrei says:

    video formats: avi mp4 mpeg mpg flv

  96. S Mirza says:

    Worked perfect for me! Thanks

  97. Hi I changed the file to different formats but it wouldn't open…I tried pdf, xls, doc, jpg, png, gif, pdf but it couldn't be opened! plz some more examples to open .DAT files…thanks..Nadeemdg

  98. Ricardo says:

    Thanks for your help. I was able to open it with Word after learning from the sender that she had created it with that program although on a Mac. I wonder if it has anything to do with that? Thanks again.

  99. Jason says:

    Trying to open a .dat file that is a backup of the yahoo im archive. Tried all of the suggestions above to no avail. Please advise with more options. Thanks.

  100. Shell says:

    I was sent a christmas card in an e-mail and it came as a DAT file I searched and found this site :

    and it opens the .DAT file for you..worked and was easy!

  101. Fabiola says:

    Thanks so much for this article! It really helped!

  102. chethan says:

    Thank you so much for clearing .DAT problem

  103. christian says:

    very awesome post!!! This really helped me!!! :) Thanks!

  104. Thanks says:

    Thanks for your help :) I was able to open a DAT file someone sent me.

  105. Marc says:

    What the hell is arbitrary data? Is that like a non-sequitur? Why doesn't the document tell you what you need to open it instead of making you "figure it out".

    Who the hell came up with this?

    Make it go away, NOW

    Why would it turn an MS Word Document into a .DAT file?

  106. pinpin_huang says:

    it works!! thx for the info.. +1 knowledge hehe

  107. be1st says:

    How can i open someone elses Yahoo Messenger archive files?

  108. mayukh says:

    Thanks mate. I was able to convert my .dat video files into workable mpg files for my office presentations. thanks again

  109. Isabel says:

    This was really helpful, however my problem is someone sent me a large file through PDF which came through as 5 smaller DAT files. When I converted them to PDF it tells me they haven't been decoded correctly. Is there anyway I can view them, or more importantly forward them on knowing they can be viewed?

  110. neil says:

    just right click, save as, delete the dat suffix and it should leave a recognizable one such as a jpeg. for example- 001.jpeg.dat should be saved as or renamed as 001.jpeg. thats my experience.

  111. Selim says:

    If it's a data file then try to open it by dragging it to Notepad. If it's a media file then you should try VLC player.

  112. Pardeep says:

    There's always a .dat file in the CONTENT 1E.5 folder inside the Temporary internet files folder. What do you open that with??

  113. Rohit2 says:

    I have a file called autorun.dat that my game FIFA10 requires, but it is not working. What extension do I need to change the file to?

  114. james says:

    Thanks. Two years after your posting and it is still proving very helpful! I just opened a DAT file as a JPG with ease. Thanks again.

  115. bum says:

    i've just installed command n conquer 4. but then i dont like it. so i want to uninstall it. but there is an error during uninstalling. it appears that autorun.dat is missing. whaat should i do??

  116. Mali says:

    I have tried to use Intenet Explorer and it worked well!

    Thanks for the suggestions though!

  117. Prashant Kadam says:

    I think .dat file may be jpeg file compacted in dat. If you try to open in winmail reader it might be open. good luck.

  118. ankit says:

    Thanks for the article! I didn't know what a .DAT file was, but your post really helped me figure it out. Thanks!

  119. melissa says:

    I have this mac video that was sent to me through my sister and i can not open it :( on a PC the title of the file is

    3887 Ko Télécharger

    Let me know how can i open it . It is a .DAT file when I see it on the Mac.

    thks in adavnce


  120. Anit says:

    I have tried all known extensions, but the file will not open. In Notepad, it's some kind of unknown font and I have tried changing font, but it does not work. What to do?

  121. ted says:

    Opened in notpad. Its a pdf file mislabled.

    Simple solution to what could have been a headache.

    Thank you.

  122. Richard says:

    I've got a ton of .dat files on my computer – which is getting so slow. Can I just delete them all or will I get in trouble?

  123. Sally says:

    That was really helpful – I managed to open the .DAT files. thank you very much!

  124. kls says:

    i just submitted an online application and i need to submit a print on the appointment date. But the submitted copy is saved in my computer in .dat format. I am not being able to open it even if i change the extension to doc or jpeg. could you suggest me how can i open this file and print it?

  125. Mike says:

    Hi, I have a set of DAT files that I need to restore. I used the File Transfer Wizard which created a number of 2GB DAT files. My concern is that each DAT files holds a number of different files (.mpg, .doc, .xls) so I can't just change the extension. Any ideas of how I could restore these as the Wizard is not being helpful at all…

    Thank you

  126. Dave says:

    DAT files are related to digital storage media. This would be more likely to be an issue on the target computer relating to file associations.

  127. Steven says:

    DAT files that accompany emails are usually created due to using Microsoft Outlook and then trying to open the email on a non-microsoft plaftform. One suggestion is to check such emails using microsoft outlook.

  128. Yukia says:

    I got a .dat file on my pc, I opened it in notepad and it had some english as well as some "I"s but nothing else, is there a specific type of editor I need to view it?

  129. Viv says:

    I found your information quite helpful especially noting it could be a JPG. The file was AC.DAT looked up your info opened it with Microsoft Office Picture Manager and it opened with the scanned document so that I could print it off. So good!!

  130. jamal says:

    actually i want to open one of my yahoo messenger archives. It is in .DAT format.

    Plz help me i dont know how to open this file, i tried my best but its not opening, soo i need your help!


    Jamal ahmed

  131. Laurie Olsen says:

    It worked on my DAT file! Thank you so much.

  132. Helpneedy says:

    PLZ HELP ME!!!!!!!! I have found my chat history in the form of .DAT files. I'm talkin about SKYPE CHAT HISTORY here… can anyone tell me how to open them in a readable format? i tried everythin above and still it wont work. Note pad only shows encoded stuff…. PLZ HELP!!!!! :(

  133. Hilary Pogson says:

    Thank so much for your advice it worked! I was sent some pictures on a .dat file but I've saved them as jpg and I can now view them.


  134. Mindaugas says:

    Thank you very much!!! I was trying to change it to JPG, PNG, GIF and finally on PDF it worked out! :)

  135. Karen says:

    I was not familiar with .DAT files and an email program changed my Excel file to a dat file which I could not open. I knew I needed to change the file type back to xls but was not sure how to get to it. Your instructions on how to "see" the file types and change it saved me. Thank you!!!

  136. Philippines says:

    Thank you so much!!!

    NOW IT WORKED, ha ha ha! using klm player for any media file,


  137. Jeroen says:

    But what if i want to open a sonic riders (PC) .DAT file? cuz i want to edit Shadow's colours and i dont know how…HELP ME PLEASE!!!

  138. Carin says:


    I have a question about opening the .dat file in excel. i can open the file ok and read the data, the only problem is that all the data on one row is in the same colum (instead of in 5 separate boxes) which makes it kind of hard to use the data for calculations… is there an easy way to fix this so that the data is in separate boxes? (right now the data from the original boxes are separated with just a space)

    Hopa someone has an answer for me!

  139. Rachel says:

    This post was fantastic, thank you so much! I had no idea you could just change file types that easily.

  140. sanjay says:

    thank you…i didnt know it was that simple…i guess you made it sound simple….

  141. Nick0824 says:

    Downloaded a database file of records supposedly in ASCII format for SPSS. Format is similar to EXCEL Files and can be used in EXCEL worksheet. File appeared as .DAT. Every time I try to open it as you suggested, I receive a message that the file is in use and cannot be opened. Any ideas on why I am getting this message and how to fix it would be appreciated!

  142. vinayakam says:

    i have a lot difficulties while try to open .dat files. my pc shows many files as cannot open. now am able to change their names and open thru media player,vlc,and so on. your suggesion is really superb! thanks s lot.

  143. Viswa says:

    Hai… Your reply really helped me… urs is the best found answer.. thanks..

  144. Carol says:

    Thank you for this! Simple and effective explanation.

    I just found your website and it went straight to my bookmarks!

  145. Rob says:

    Thanks a ton. you helped me solve my .dat file problem. Couldn't have done it without ya.

  146. hasan says:

    my .dat extention file for video is not opening with any media player.What can I do for opening those video file

  147. rama says:

    Hi, I want to open a .dat file that I got in an email. I followed your instructions, but it's not working. I went to Tools, Options and show hidden file extensions and then changed the ending to Word, Powerpoint, Excel, Notepad, Wordpad, JPG, AVI, but nothing is working. I cannot read the DAT file. Please help me.

  148. Joe Don says:

    Got a .dat file with an attachment drafted in Word 1973 -2003. I am using MS Office 2000 Small Business. Followed your very clear instruction. Changed the .dat to .doc and got unintelligibe characters. Any suggestions?

  149. Kathy says:

    I have just been struggling to do the same, and finally it worked after a lot of failed attempts to change the .dat to .doc. What I did was:

    - right-click on the file name as stored in the folder

    - go to 'Properties' (the 'General' tab)

    - click on 'Change' and select Word

    - click OK

    - open the file, which will now have a .doc extension.

    This worked for some reason, while manually changing the extension and/or using 'open with' didn't.

  150. Joe Don says:

    Kathy, As you suggested, I saved the winmail.dat to a folder, right clicked , selected properties and got "The properties for this item are not available." Couldn't get to "general" tab to click on Change.

    Thx. I'll just have to keep trying.

  151. ramesh says:

    Thanks. It's working.

  152. Aman Rana says:

    Really very nice site (post)…on opening DAT files…

  153. lukre says:

    I needed to open a .DAT file to translate something sent to me and you really saved me! thanks a lot!!!

  154. dhana says:

    My friend's windows corrupted, so I removed the hard disk and installed in another computer to retrieve data. But all the data were in .DAT file which I could not be able to open in any programs as there were too many types of files in the HDD. How do I open the .dat file so that I can delete unwanted files and save the important data before reformatting the HDD.

  155. Rakesh says:


    I have one software module which accepts only .DAT files (Images taken from a specific camera). Now, I want to open another images with same module. I converted JPG and TIF files to .DAT, but it still shows "invalid file format." Is there any generic reader for .DAT files?

  156. Nicole says:

    This is really helpful, but I can't figure out what type of file it's supposed to be. I have a CD I burned 5 years ago (when I was only 10) and it was supposedly supposed to be a bunch of stuff from Teen Titans (a TV show I loved). I've tried all the different extensions I would have used at the time (.gif, .jpg, .bmp, .doc, .wmv, etc.), but I still can't figure it out. The odd thing is that when I first put my disc in, it says it's a video disc, so I'm thinking it's supposed to be some sort of video.

    Any ideas? If so, please email them to me!

  157. beti says:

    # Helpneedy said on : April 13th, 2010 at 12:47 am

    "PLZ HELP ME!!!!!!!! I have found my chat history in the form of .DAT files. I’m talkin about SKYPE CHAT HISTORY here… can anyone tell me how to open them in a readable format? i tried everythin above and still it wont work. Note pad only shows encoded stuff…. PLZ HELP!!!!! :("

    I have the same question. Can anybody help?!

  158. Liz? says:

    I downloaded a bunch of notes from Outlook and wanted to open them in Excel. Can that be done?

  159. Asparuh says:

    It worked. I changed the file format .dat to .doc, and, as I was expecting, the document opened perfectly with Word.


  160. Hugh says:

    Many thanks for the advice. It was invaluable!!

  161. srinath says:

    This is just to say thanks for the tip provided. I was able to open the .dat file.

  162. Sandi Parks says:

    How to open a .dat file received as an email attachment: I save the file to my desktop and open it with Internet Explorer.

  163. Kiran says:

    I am trying to edit a game file with the extension .DAT and I have searched everywhere on the internet but can't find anything. I want to edit the .DAT file to customize the game to have more lives, more points, etc.

    Can anyone help?

  164. Jorma Smith says:

    I have a .dat file from a game. The file is about 300 megabytes and, if I try to open it with Notepad or Word, the programs always crash, maybe because the file is so big. Is there any way I can open that file?

  165. Audrey Tromp says:

    This is an awesome site and the above explanation you gave is what I have been looking for for a very long time so because of this, I have a question that I pray you can help me with … Here we go!

    I have just purchased Corel PSP Photo X3 and I absolutely hate it! It was installed on my computer, worked okay for only a week and then just bombed out. I click on the icon, it goes into the program for a split second and the disappears. Our computer guy has tried everything but nothing is working and I cannot read any of the graphic files that I need to make my cards from. We have uninstalled and reinstalled 11 times and nothing is working!!!!

    Is there a solution or better still is there a program that I can downbload to enable me to read these PSP files and delete Corel completely.

    If you can answer this question, I will be dumbstruck because nobody else is able to help me.

    Thanks for a great site which I have added to my favorites and forwarded to my friends.



  166. Aaron says:

    Excellent guide on this, for those people asking about autorun.dat files and modifying .dat files that come with software, these files are not meant to be viewed except by the software and editing these files can cause major problems with your program.

    One of the best ways to think about those type of .dat files is to think about secret codes used by military etc.

  167. Monika says:

    hey i cannot open this .dat file. I have tried a lot to open it but i think its windows media player but it makes weird noises so please let me know if you can do anything. i have provided you my email so just contact me via that so that i can send you that attachment!! please help me asap! thnx

  168. seha says:

    I have tried changing my CHAT MESSAGES archives to .doc, .txt, .pdf etc, but NOTHING MENTIONED here for CHAT MESSAGES ARCHIVES works!

    Others have also pasted the same query, but only for this i have not been able to find a solution. This is really very important for me.

    Please do help. Will be grateful.

  169. christina says:

    great help! thank u :)

  170. Sachin says:

    Thank you, thank you, thank you. was fighting to open this dat file since morning.. finally done. thanks for this informative article. thanks agian

  171. Billy Derka says:

    Thanks for the tip. It was a life saver.

  172. apit john says:

    Thanks…I just found out mine is a PDF…

  173. sweety says:


    I have several files: .DAT, .ATR, .HEA, but they may be video or data files. Some are database files. I don’t know anything else about the files. Can anyone tell me how to open or see the content of these files?

  174. TomG says:

    I have a golf GPS system from IZZO Golf that works fine until I attempt to update it with golf course edits. The update download is filled with .dat files. I’ve tried all programs I know to get the device to function but message I get is: “NO META DATA” and device becomes worthless. Support from IZZO just sends me another Swami 3000 (name of model) and cannot help me beyond that. Any ideas?

  175. Srikhaing says:

    while doing an IP CAMERA test with a tplink3230n, backing up some scheduled recordings is ok, but the backing up process saves to .DAT file by default, I have no choice). I have no idea how to play those files back…any idea?

  176. maja says:

    Hi Aseem!

    Thank you for the tip :) Extremly helpful! I tried to open my dat. file in Word and it worked.

  177. Gwen Dolen says:

    Thanks so much for this information. I had no idea that a DAT file could be opened by so many different programs. Awesome help!

  178. Taleh says:

    Thanks for your clear instructions. It helped me open my file.

  179. Sminky says:

    It worked just as you said. Just change the extension to the desired file format, then it opens perfectly. Thanx a great deal.

  180. ksraveendra says:

    The given details and procedure to open .DAT files has really helped. Thanks

  181. Rosita says:


    I have done this, but it didn’t work and I got a message that it is a corrupted file!

    Please help me?

  182. RDWC says:

    I am playing a mahjongg game. I have gotten all achievements except one. The last one says I need to reach 13,000 points to get the achievement. I am trying to change the points to 12,000 or 12,500 so it easier to do. When I open the DAT file and change it, it won’t open the game correctly. Any suggestions ?

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