Ubuntu – Boot-repair it not detecting windows and hence no grub menu item for booting windows

dual-bootgrub2kubuntuuefi

I have problems getting kubuntu installed and dual boot together with windows 10. I have two disks one for windows and one kubuntu. I would like to have grub installed on the kubuntu disk and have it dual the windows.

Boot-repair gives this output:

http://paste.ubuntu.com/p/CcFgmQ3xY8/

I have tried the os-prober, grub update and boot-repair but none of them gives a installation that produces a grub menu item to boot windows. If I change my bios to boot the windows disk it works fine. Booting the ubuntu goes fine from the disk with grub/kubuntu.

It looks like I need the boot-repair to find my windows installation before I can get this to work. But how?

Best Answer

EFI partitions are your friend, one per drive:

  • FAT32 format
  • About 200-400MB
  • "boot" flag

Windows usually handles this itself.

With *ubuntu, create/verify it manually on your disk in GParted in the Ubuntu Live USB/CD before entering the Ubuntu installer.

Not sure if that helps this specifically, but that's how I would have tried to avoid/solve this. It may help others with a similar problem.