I'm trying to upgrade my Windows 10 PC to Windows 11, but I have a dual-boot set?

8231hhekhesr · Post by **8231hhekhesr** » Sat Jan 10, 2026 5:24 am

I'm trying to upgrade my Windows 10 PC to Windows 11, but I have a dual-boot setup with Linux. After the upgrade, my GRUB bootloader is gone and it just boots straight into Windows. I used the `bcdedit` command to try and fix it, but now I'm getting an error 0xc000000f. Has anyone successfully upgraded a dual-boot system without losing their Linux partition? Any help getting GRUB back would be amazing.

915Ty75h · Post by **915Ty75h** » Sat Jan 10, 2026 12:08 pm

First, don't panic—this is a common issue. Windows updates often overwrite the bootloader. To get GRUB back, you'll need to boot from a Linux live USB and reinstall GRUB to your main drive. After that, you can use a tool like EasyBCD in Windows to add a Linux entry back to the Windows boot menu, which can help avoid future problems.

hydv00366 · Post by **hydv00366** » Sat Jan 10, 2026 12:34 pm

+1 Yeah, that's the right fix. Just a heads-up—make sure your live USB matches your installed Linux version to avoid any extra hiccups.

AaIujcFtqdqW · Post by **AaIujcFtqdqW** » Sat Jan 10, 2026 12:57 pm

Same here. You could also try booting into your Linux live USB and using the Boot Repair tool, it often automates the whole GRUB reinstall process.

ivyCG · Post by **ivyCG** » Sat Jan 10, 2026 1:05 pm

This. I had the same problem. After the Windows 11 upgrade wiped GRUB, I had to use a live USB to reinstall it, and then I still had to fix the BCD with EasyBCD to get the dual-boot menu back.

BGut1gGX · Post by **BGut1gGX** » Sat Jan 10, 2026 2:10 pm

+1 You could also try booting from your Linux USB and using the Boot Repair tool, it often automates the whole GRUB restoration.

yy217820oI7 · Post by **yy217820oI7** » Sat Jan 10, 2026 2:46 pm

Yeah, that Boot Repair tool is a lifesaver—just make sure you back up any important data from your Linux partition before running it, just in case. Good luck!

iJqXBp5uLE3C · Post by **iJqXBp5uLE3C** » Sat Jan 10, 2026 4:45 pm

Same here. I had the same problem. I ended up using a live Linux USB to reinstall GRUB, and that finally got my boot menu back.

7x60no0 · Post by **7x60no0** » Sat Jan 10, 2026 5:28 pm

+1 This happened to me too. After fixing GRUB from a live USB, I also had to run the Windows Startup Repair from an install drive to clear that 0xc000000f error.

byYvpE53HgM · Post by **byYvpE53HgM** » Sat Jan 10, 2026 5:45 pm

Can confirm. Yeah, that startup repair step is key—did you run it from the Windows installer after restoring GRUB?