How to set active partition in Vista and XP

Posted on December 23, 2008 at 5:54 am

Do you have multiple partitions on your computer with different operating systems installed? If so, you can change the active partition in Windows so that when the computer starts up, it will load the appropriate operating system.

Changing the active partition is a fairly advanced task, so if you are planning on doing this, you probably didn’t need the explanation above! Only change the active partition if there is a operating system residing on that partition, otherwise you will have a non-working computer.

Also, there are a few things to note about marking a partition as active:

  1. A logical drive or extended partition cannot be marked as active, only primary partitions can be changed to active.
  2. You can only have one active partition per physical hard disk. Doing otherwise will cause all kinds of problems.
  3. If you have several physical hard disks on your computer, you can mark a partition as active on each disk, but only the active partition on the first hard disk detected by your BIOS will start up the computer. You can go into the BIOS and change the order to detect hard disks.

Set active partition in Vista and XP

Open Computer Management by going to the Control Panel, clicking on System and Maintenance, and then clicking Administrative Tools.

computer management

You can also just click Classic View and then choose Administrative Tools. Now click on Disk Management under Storage.

disk management

Right-click on the primary partition that you want to mark as active and choose Mark Partition as Active.

mark partition as active

Set active partition using command line

If you screwed something up in Windows and marked the wrong partition as active, you will no longer be able to boot your computer. In the case where you cannot mark a partition as active using Windows, you’ll have to us the command line.

First get into the command prompt using a boot up disk and type diskpart at the prompt.

diskpart set active partition

At the DiskPart prompt, type in list disk. You will see the list of disk currently attached to your computer. Now type in select disk n, where n is the disk number. In my example, I would type select disk 0.

diskpart select disk

Now that we have selected the correct disk, type in list partition to get a list of all the partitions on that disk. To select the partition we want to set as active, type in select partition n, where n is the partition number.

set active partition xp

Now that we have selected the disk and partition, we can mark it as active by just typing the word active and pressing Enter. That’s it! Now the partition is set.

Most people are familiar with using FDISK to mark a partition as active, but that is now an older and out-dated method. You should use DISKPART to manage disk and partitions on a Windows XP and Vista computer. Enjoy!

» Filed Under Computer Tips

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Comments

18 Responses to “How to set active partition in Vista and XP”

  1. Rachael said on : February 7th, 2009 at 1:36 pm

    Thank you, this was very useful! I am transferring files from one drive to another, and this has saved me loads of grief.


  2. Eric said on : March 18th, 2009 at 9:00 am

    How do you undo this action. after setting it to active my PC will not boot. I have to boot with the windows disc in.


  3. kjv1611 said on : May 29th, 2009 at 6:12 am

    To Eric (though I know this is a wee bit old by now, and therefore probably too late):

    Boot from something like the Ultimate Boot CD or else a live Linux distro, and set the correct partition as active from there – that should take care of your issue, I believe.


  4. Adrian said on : October 24th, 2009 at 4:29 pm

    Thank you. The cmd part I did not know.


  5. Al said on : October 24th, 2009 at 10:00 pm

    Thanks SO much. This was exactly what I needed. I was
    cloning a partially bad drive to a new one using xxcopy.
    I also did FIXBOOT and FIXMBR (not really knowing what I was doing) and the new disk was still not recognized for booting. All it needed was to be declared ‘active’. A little prayer (ok, a big one) and your solution and viola!
    Now my computer is booting off of the new disk! :)


  6. Lily said on : November 25th, 2009 at 12:26 am

    Here is a free partitioning software that will help you to change the partition to active in one click:

    http://www.partition-tool.com/personal.htm


  7. Carol said on : January 9th, 2010 at 8:46 am

    Thank you Lily-you were a life saver! Other post extremely appreciated.


  8. CARLOS said on : January 9th, 2010 at 6:14 pm

    Hello, I desperately need help! I have two partitions on my hard drive, one with Windows and one with Windows Vista. I didn’t know you could set more than one partition to active, which I did by mistake and now I get an error when I try to boot. I can only get into the BIOS. My email address is colordisco @ gmail .com. Thanks!


  9. John said on : February 8th, 2010 at 1:11 am

    I also found that you can also set a partition inactive under diskpart.


  10. Phlip said on : February 16th, 2010 at 5:30 am

    Thanks for this! Crazily, the Disk Management GUI won’t let you set partitions that Windows doesn’t recognise (say, a Linux partition) as active… happily, the CLI tool didn’t think it knew better than me, and let me do what I needed to do.


  11. Oz said on : March 15th, 2010 at 2:38 am

    This was very helpful! I just installed another hard drive on my PC that already have Windows 7 installed on it. Wanted to set that as the active partition to boot between the two operating systems.


  12. road said on : April 12th, 2010 at 10:40 pm

    Thanks! After a few hours of messing with fdisk and fixboot this finally worked! Great, clear and concise instructions.

    I’m very grateful.


  13. john said on : May 1st, 2010 at 9:13 am

    Question. I have 3 hard drives in my PC, with the system on the C: drive and the other drives (D:, E:) are used for data storage. Using partition software, I noticed one of the storage hard drives is listed as ‘active’ and ‘primary’ (as well as the C: drive with the OS on it)….should that be changed to ‘non-active’ or ‘extended/logical’ drive? Notice, these are partitions, each of which, occupy the entire drives of 3 different hard drives.


  14. Bedford said on : May 1st, 2010 at 2:51 pm

    Hi,
    very usefull site. I changed the active partition of the main and unique OS disk to the one without OS and I can’t start anymore. The diskpart shipped with the XP install disk doesn’t allow to set the active partition, only create and format partitions.

    So unfortunately this option doesn’t work.


  15. Bahman M said on : May 4th, 2010 at 11:07 pm

    Very useful. Much appreciated.


  16. antonio said on : June 21st, 2010 at 11:11 pm

    hi,
    i bought a compaq evo n1000c on ebay with windows xp, i’m tryng to set it up but when i turn the pc on the screen goes blank and gives me

    BOOTORG
    NO ACTIVE PARTITION

    i’m going crazy and i dont know how to fix this, if anyone can help me i really approciate.
    thanx


  17. Tarang said on : September 8th, 2011 at 9:58 am

    Thanks Bro….It’s working
    I have to active that partition to install vista.

    THANKS VERY MUCH !!


  18. alex said on : September 11th, 2011 at 8:24 am

    thank you- that easy walkthrough saved me- was googling for an hour or so before i ound this… i had major trouble after running several hackintosh installations a linux and my main win7… my system changed drive etters from c: to e: anf made e: inactive… i was playing arount fixing boot ecords aso.. nothing helped- i could not get into win7 anymore- and im not at all unexperienced when it comes to system management.. well everyday you learn something new XD. thanks a loti hope posting this moves this thread up a few places in google… somebody else might find it as useful as i did) almost anywhere else you read just: well, you gotta rebuild your system from scratch… NO- YOU DO NOT- JUST ASSIGN ACTIVE STATUS TO THE PARTITION OF YOUR CHOICE…. THANKS AGAIN


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