In the process of trying to shrink my hard drive partition, I marked my C: drive (the only drive I have) as “active” in Windows’s “Disk Management” software. When I rebooted, it said something like “boot device not found” (can’t remember the exact wording).

I can’t boot into Windows, but I do have a Linux Mint cd that I’m on right now. From my research, it looks like the equivalent of “Disk Management” is GParted.

So the question is, how can I undo marking the partition as active (within Linux) and be able to boot into Windows again?

Right now GParted looks like this:

enter image description here

  • Not asked, but probably the easiest workaround: Press whatever key your firmware used to select to boot from and just select the other active drive.
    – Hennes
    Oct 30, 2015 at 15:07

1 Answer 1


It's the same flag. The "active" flag in Windows is called the "boot" flag in Linux.

Windows and Linux use different terminology for the same bootable partition or drive

The term "active" is used for the bootable partition when you are in a Windows/DOS-type environment.
The term "boot" is used for the bootable partition when in a Linux environment.


You can modify the flag in GPartEd by right-clicking the partition and selecting "Manage Flags". To undo the boot flag, uncheck it with the C: partition and add the boot flag on the System Reserved partition.

enter image description here

  • So I unchecked that and rebooted--got an error saying "reboot and select proper boot device". I'm confused because shouldn't the partition be flagged as boot, since it's the only one? But having it flagged as boot also doesn't allow me to boot. Oct 30, 2015 at 15:27
  • Now you have another problem. The partition you marked as boot isn't bootable.
    – Joshua
    Oct 30, 2015 at 18:01
  • 1
    The Windows recovery disk should be able to fix the bootloader, in theory.
    – Kevin
    Oct 30, 2015 at 18:21
  • @Kevin I was hoping this could be solved with GParted, is that not possible? Oct 30, 2015 at 18:49
  • @ahota: The Windows bootloader is proprietary software. While it has been reverse-engineered to a limited extent (allowing for dual booting), it's not really possible to reinstall it without using Microsoft code, to the best of my knowledge.
    – Kevin
    Oct 30, 2015 at 18:51

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