0

I installed Ubuntu on an existing Windows 10, dual boot was fine for some months. Now I try again and it doesn't work anymore. grub-update doesn't find any OS besides Ubuntu. Using boot-repair from a USB-Stick finds the EFI partition on nvmen1p1, but booting from that results in

error: can't find command 'parttool'.
error: can't find command 'drivemap'.
error: invalid EFI file path.

nvmen1p2, where the real Windows 10 is located, is not found, even from the USB stick.

sudo os-probe on regular Ubuntu finds nothing.

Here is the pastebin: https://paste.ubuntu.com/p/H54w8bCwws/

Any advice?

G. S.
  • 115

2 Answers2

0

Add it manualy in your grub.cfg. Add

menuentry "Windows 10" --class windows --class os $menuentry_id_option 'osprober-efi-F024-2799' {
insmod part_gpt
insmod fat
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root F024-2799
else
search --no-floppy --fs-uuid --set=root F024-2799
fi
chainloader /EFI/Microsoft/Boot/bootmgfw.efi }


below the line ### BEGIN /etc/grub.d/30_os-prober_proxy ###. It can be another number than 30, but 30 is the most common number for os-prober.

Remember that after an sudo update-grub you will have to do this again. And also make backup first.

If it works please accept the answer. If it doesn't, report back and we will look for other options.

HomerSimpson
  • 537
0

I got it working again. Rough steps:

  1. Add small GUID partition at the beginning of the disk.
  2. Download Windows 10 and install on external hard disk.
  3. Run from there and repair (had to go down to the command line and follow some advice I found elsewhere, can't remember).
  4. Now I can switch between Windows and Ubuntu in
G. S.
  • 115