Use Windows Defender Offline Tool to Fix an Infected PC

I had a client the other day whose PC was practically dead because they clicked on one of those pop up ads while on some sketchy website. Something got downloaded and their computer was infected with malware and wouldn’t load properly. When trying to log into Windows, they kept getting some error like the one below:

Interactive logon process initialization has failed

Who knows what that means. Anyway, they could no longer get into their Windows 7 machine and because of that there was no way to remove the spyware from the computer. They could not even log into Safe Mode to run an anti-virus program. So the only options were to delete everything, reinstall and start fresh or try to use some offline spyware scanning tool to remove the malware before Windows even got a chance to boot up.

Luckily, Microsoft released a cool offline version of Windows Defender that scans your system outside of Windows and removes any infections. Then you can start up your computer and the malware will be gone and hopefully your system will start up normally! That’s pretty cool and definitely better than having to reinstall everything.

Offline Virus Scan

To get started, go ahead and download the Windows Defender Offline tool here:

http://windows.microsoft.com/en-US/windows/what-is-windows-defender-offline

The way it works is that you download a program that will help you create a CD/DVD or USB bootable media that runs Windows Defender. You’ll create the media and then boot your computer from the CD or USB drive, which will then scan your system and fix any problems.

Once you download the 32 or 64-bit version, run the program and you’ll see the welcome screen:

windows defender offline

Go ahead and click Next to get started creating the offline media. Once you accept the license agreement, you’ll be given the option to install Windows Defender Offline on a CD/DVD, USB flash drive, or to download an ISO file.

remove malware

I installed it on a flash drive, which will have to be reformatted in order to install Windows Defender Offline. You only need about 250 MB of free space on the flash drive, but it will still format the entire thing.

reformat usb

Click Next and the process will start. It will download, then process the files, then format the USB drive and then install the files.

install windows defender

Once it’s complete, you will see the instructions for how to use the new media:

usb flash drive

Now you can boot up using the media and you’ll get the familiar Windows Defender screen. If your computer doesn’t automatically boot to the USB drive, you’ll need to change the boot order in the BIOS first.

Note that all the definition files are downloaded when you use the install tool. You don’t need an Internet connection or anything in order to update the definition files. If you need to run the tool again at a later time, you need to create the media again because it will download the latest files and then create the bootable media.

windows defender

Hopefully, the next time you have a problem with your computer and you know it’s spyware or malware, you can use the offline tool to disinfect your system. If you have any questions or problems using the tool, feel free to post a comment! Enjoy!

Comments [7]

  1. Thank you for this valuable tool!

    I would just like to know how to boot from this drive. Do I just insert it and the system will start from the USB drive, or do I need to poke around in the system BIOS (or EFI)? Thank you.

  2. Feel so dumb asking this, but here goes… if this problem should ever happen to me, how do I boot up from a USB flash drive? I have Vista Service Pack 2.

    Hope someone answers my question as I am going to download Windows Defender to a USB flash drive. thank you! ­čśÄ

  3. So easy, so fast, so good, so thankful for this article!!!

  4. @Frank, @Marie – Those are not dumb questions! I have written about how to change the boot order on your PC in a previous article on my other site, Help Desk Geek:

    http://helpdeskgeek.com/how-to/change-boot-order-

    You do have to enter the BIOS and change the boot priority there. If you have any questions or get stuck, feel free to post another follow up comment. Thanks for visiting!

  5. Can I use Windows Defender although my Windows XP SP2 is not a legal version?

    Is this better than Kaspersky Rescue Disk 10 or AVG Rescue CD?

    I like it’s not necessary an internet connection, as it is with Kaspersky Rescue Disk 10 or AVG Rescue CD, which I intend to use in a desperate case.

    Over 1 month I have a bad infection with rootkit siszyd32.exe, whose name appeared only in ComboFix log, only in Reg Loading Points: HKLM\…startupfolder\username….

    This trojan was not detected by MBAM, Kaspersky Virus Remover Tool, FreeFixer, Trojan Remover, GMER, SmitFraudFix…and many others.

    Thank you for your help!

  6. My sister-in-law had a Trojan virus and was caught by windows defender. Could not remove and suggested using Windows Defender Offline. I ran the Defender Offline program and did remove the Trojan however, at bootup it keeps wanting to run the Windows 7 repair tool. Try to boot normally but will not. the repair tool seems to indicate “CHKDSK” had errors. Sorry I don’t remember the exact wording. Question, is this becoming a hardware issue? I don’t have the original disk’s for reloading everything…..

    This is vague but hoping to get a few suggestions.

    Thanks so much for any response.

  7. Have you run the repair tool? If not I would recommend doing so, just let it do it’s thing and hopefully move on. Someone probably tried to run chkdsk and couldn’t for some reason and opted to run it on the next reboot (possibly without knowing or remembering). Once you’ve asked it to do so it will want to do just that so let it. I realize this is an old post but if anyone else should run across this thread with the same issue maybe it will help. If you’ve run it and are still having issues then post back. It’s helpful to post error messages verbatim, and also the name of the infection that was the issue to begin with. Some malware will turn off services or delete system files so that even when it’s gone you still have problems.

    Good luck

    P.S. I don’t recommend products often but I like this tool. It’s a definite keeper.

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