1

After running a stable dual boot system with Win7 for years, I had to upgrade to Win10 recently. Windows worked but as anticipated, destroyed the grub loader. I restored it via chroot method and can now boot Ubuntu, but Win10 no longer works. Selecting the correct entry results in "cannot find image". OS-Prober does not find Win10. Even Microsoft's own bootrec cannot find Windows now!

sda1 Windows
sda2 /
sdb1 EFI system.

And this is how the Win10 entry in grub looks like:

menuentry 'Windows 10' {
    search --fs-uuid --no-floppy --set=root **the UUID of sdb1**
    chainloader (${root})/EFI/Microsoft/Boot/bootmgr.efi
}

Of course I could now go and reinstall Win10, but that would only get me back to square one. I have tried out turning secure boot on/off and starting windows from bios. Nothing makes a difference.

Edit: I am quite certain that I installed both systems in EFI mode, non secure, way back when. This time round, I made sure to install Win 10 in EFI mode and ran the USB stick in EFI more too for the grub repair. Here's the link to the boot summary: https://www.dropbox.com/s/9np4100t8lgf0v3/Boot-Info_2019-07-09__12h26.txt?dl=0

Edit II: My initial post was bit sloppy. I did not upgrade the Win7 installation to Win10; Win10 was a clean install into sda1 that was previously occupied by Win7.

Tom
  • 11
  • 3
    Almost all Windows 7 systems were BIOS on MBR partitioned drives. Windows will only boot in UEFI boot mode from gpt partitioned drives. Did you reinstall Windows 10 in UEFI boot mode to gpt drive? You cannot mix BIOS & UEFI on same drive and best not to on same system. May be best to see details, use ppa version with your live installer (2nd option) or any working install, not older Boot-Repair ISO: Please copy & paste link to the Boot-info summary report ( do not post report), the auto fix sometimes can create more issues. https://help.ubuntu.com/community/Boot-Repair – oldfred Jul 08 '19 at 22:47

0 Answers0