Yeah this is common. First, make sure your PC meets all the Windows 11 requirements, especially Secure Boot and TPM 2.0, as those can cause weird errors. That error code often points to a storage or file system issue, so try running the Windows Update Troubleshooter from your Windows 10 side. The upgrade should only touch the Windows partition, but to be extra safe, you could temporarily disconnect or disable your Linux drive in BIOS during the upgrade. I did this on my own dual-boot machine and it went smoothly.
I'm trying to upgrade my Windows 10 PC to Windows 11, but I have a dual-boot setup with Linux. The Windows 11 installer keeps failing with error code 0x80070003. It seems to get stuck checking for space, and I'm worried it might affect my Linux partition. Has anyone successfully upgraded a dual-boot system without losing their other OS? I made backups, but I'm nervous to proceed.
You could also try temporarily removing the Linux boot entry with EasyBCD in Windows before running the upgrade. Another option is to disconnect the drive with Linux installed, if possible, to let the installer focus only on the Windows drive.
I had the same problem. I had to temporarily disable the Linux bootloader from my BIOS so Windows only saw its own drive, and then the upgrade went through.
+1 This happened to me too. After doing that, I also ran the Windows Update troubleshooter before trying the upgrade again and it finally worked. Good luck!
Yeah, that's a solid fix. One extra tip: temporarily disconnect any non-essential external drives before running the installer, as they can sometimes confuse the space check.