Mark a Disk Partition as Inactive

If you are like me then you like to reinstall Windows on your laptop every few months to keep things fresh and running smoothly.  That or your even more like me and you download some beta version of software and install it on your laptop rather than a VM and screw something up to an unrepairable state.  Either way Windows is being reinstalled.  I have a laptop without an optical drive in it.  The vast majority of the time I don’t mind as I pretty much use ISO files exclusively.  This is a problem though when reinstalling the OS.

I will usually extract all the Windows install files onto the root directory of my external hard drive, make it bootable (Mark the partition as active) and install from there.  The problem with that is you can’t just go back into the disk management console and right click and unmark a partition as active. This causes it to go through the whole auto run thing every time you plug it in and if you boot while the drive is connected it gives you a fit because it wants to install the OS or can’t find bootable files. Blah, blah, blah. So let’s just mark it as an inactive partition and get it over with. You will know a disk has an active partition by going into the Disk Management Console.  You can see in the screenshot below, my external hard drive called My Passport (the F: drive) is marked as Active.

To mark a partition as inactive follow these simple steps:

  1. Open the Command Prompt
  2. Type DISKPART (A new window will open)
  3. Type LIST DISK at the prompt and a list of disks will be displayed numbered starting at 0
  4. Type SELECT Disk # and replace the # with the appropriate disk from the list
  5. Type LIST PARTITION and a list of partitions for the selected disk will be displayed
  6. Type SELECT Partition # and replace the# with the appropriate partition form the list
  7. Type INACTIVE
  8. Either close the two windows or Type EXIT in both to close them.
The end result will look something like the screenshot below.

Bradley Schacht

Bradley Schacht is a Cloud Solution Architect on the state and local government team with Microsoft based in Jacksonville, FL. He has co-authored 3 SQL Server books including "SQL Server 2014 Professional Administration". As a former consultant and trainer, he uses his experience on many parts of the Microsoft BI and data platform to help customers deliver the best possible solutions. Bradley frequently presents at community events around the country. He is a contributor to sites such as and an active member of the Jacksonville SQL Server User Group (JSSUG).

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18 Responses

  1. Castiel says:

    best instruction thanks

  2. capncarnage says:

    You are my savior

  3. Le dicen MAD !!! says:

    EXCELENT !!!

  4. Popa Mircea says:

    Thanks a lot !

  5. Daniyal says:


  6. Okay says:

    everyone else’s solution is ABSOLUTELY RETARDED compared to this simple, fast, and effective solution… MANY THANKS!

  7. Tom O'Brien says:

    Clear and concise.

    Thank you Bradley.


  8. esther says:

    where do I find the command prompt on the Computer Management screen in order to begin typing?

  9. keepemoutBob says:

    Simple explanation which works perfectly – many thanks!

  10. TJ00 says:

    THANK YOU!!! I was an idiot and marked my hdd partition as active and suffered from ‘BOOTMGT’ (I believe) is missing. Now I am back to running after marking it inactive through CMD on my Windows Install Disk. Thanks again! Was afraid there for a second until I saw your post. Total life saver. Literally! It would have taken me a life time to find all that software again! Just to let you know that you are still a helpin’ people.

  11. DanB says:

    Thank you so much for this, saved me a lot of stress.

  12. Lance says:

    Thank you for the instruction. Spot on.

  13. Mattaeus says:

    Thanks a bunch !! Worked Great !!

  14. Eddy says:

    Wow, thanks for the advice, worked!

  15. armal khan says:

    the screen shot is very helpful thanks bro.

  16. Ali Bilal Qambrani says:

    You saved me from a lot of hassle

  17. alek says:

    thank you, for the help. a software was not recognising my drive so started messing withe Activate. Then you could guess the rest of the nightmares.

    thanks a lot for helping me revert

  1. September 2, 2012

    […] After you have done all the steps, the disk partition will now be turned back as inactive, and you can exit the session. Make sure you now select the right partition as Active, as your computer needs the boot loader to boot next time. [via] […]

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