I am unable to boot my Windows 8 partition, I have tried using boot repair several times. I no longer see the EFI folder in my Windows partition.

I have tried editing the 40_custom file:

menuentry "Windows 8 Recovery" {
   set root='(hd0,gpt2)'`
   chainloader /EFI/Boot/bootx64.efi


menuentry "Windows 8" {
   set root='(hd0,gpt4)'`
   chainloader /EFI/microsoft/BOOT/bootmgfw.efi

menuentry "Microsoft Windows Vista/7/8 x86_64 UEFI-GPT" {
  insmod part_gpt
  insmod fat
  insmod search_fs_uuid
  insmod chain
  search --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt1 1ce5-7f28
  chainloader /efi/Microsoft/Boot/bootmgfw.efi

This is the list of the partitions: http://paste.ubuntu.com/5984434/.

Windows Recovery Environment (loader) (on /dev/sda2):

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

Windows 8 (loader) (on /dev/sda4):

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

Both Ubuntu and Windows were installed in UEFI mode.If anyone has any ideas on how I can access my windows partition, thanks in advance.

  • If you have installed ubuntu in legacy mode & windows is installed with UEFI. You need to change the mode accordingly in BIOS
    – Web-E
    Aug 14, 2013 at 10:42
  • Maybe wrong quotes on the set root = ,or maybe add the $root to the path? chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi
    – ubfan1
    Aug 14, 2013 at 17:13

1 Answer 1


If you didn't type sudo update-grub after editing 40_custom, do so. Those edits won't take effect until you update the grub.cfg file by typing sudo update-grub. Thereafter, you should see three new entries, one for each of the stanzas you've defined. Try them all.

If that doesn't work, try using the USB flash drive or CD-R version of my rEFInd boot manager. If it enables you to boot both Windows and Linux, install the Debian package version in Ubuntu.

  • I did update the grub and all the entries show up I just cannot access them they give a disk not found error. I will try the boot manager or install another linux partition and try that.
    – Tai
    Aug 15, 2013 at 19:12
  • The two names you specified ("Windows Recovery Environment (loader) (on /dev/sda2)" and "Windows 8 (loader) (on /dev/sda4)" are not the same ones in your 40_custom file. Furthermore, the errors you report include can't find command drivemap; but the drivemap command is not used in your 40_custom file entries. This makes me think that you either did not type sudo update-grub or it didn't work right for some reason.
    – Rod Smith
    Aug 15, 2013 at 22:34

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