HELP needed with Grub, Windows Dual Boot Machine, but no windows boot option

Forum Forums New users New Users and General Questions HELP needed with Grub, Windows Dual Boot Machine, but no windows boot option

  • This topic has 17 replies, 8 voices, and was last updated May 15-7:03 pm by stevesr0.
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  • #142399

      hi BobC,

      I am perhaps confused.

      I believe you have two hard drives:
      sda has both Windows and Linux OSes installed on that on different partitions
      sdb has Windows data on sdb2 and /boot/efi on sdb1.

      There are two ESP partitions, one on sda1 and one on sdb1. The sdb1 has a mountpoint /boot/efi, but the sda1 does not.

      Running the chainloader script assuming that the Windows EFI file is on sda1 doesn’t work.

      Some basic questions:

      (1) Is there a /BOOT/EFI/BOOTX64.EFI file in sda1?

      (2) Is this a fairly old system (originally Win7)? If so, MS says you might have to boot by browsing to the
      \EFI\BOOT\BOOTX64.EFI file and try to run it from there.

      (3) Can you access the BBS menu item in the sda BIOS or the sdb UEFI? That might have an entry within it to boot the Windows EFI file.

      (4) Is there a Windows Boot Manager entry in the BIOS for sda or in the UEFI in sdb?

      (5) Is there a list of bootable choices if you hit one of the function keys after turning power on (I am used to F12). If a menu appears, does it include a choice to boot Windows?

      • This reply was modified 1 week, 6 days ago by stevesr0.

        There is no Microsoft folder in either sda1 or sdb1. There is a \EFI\BOOT\BOOTX64.EFI folder and file. It is quite possible that the system was originally Win/7 and upgraded to Win/10 later, and because I didn’t install any of it other than antiX-23 and then replaced that with antiX-21 last week, I don’t know what was done before that.

        Is there a command I could run (I assume you looked at the bootinfoscript results file I attached already) to show the partition info and complete directory listing for sda1 and sdb1? There aren’t than many files on them.

        I think I already posted the list of boot options. Neither of the 2 non-Linux options will boot if I select them. If you tell me the commands to use to show what is bootable from the grub rescue > prompt, I could run them and post the results. I don’t know how to boot it from grub rescue.

        Daily driver distro


          Hi BobC,

          (1) re: booting the BOOTX64.EFI file. I found this mentioned in a post by Microsoft (link: It says that for systems that were Win7 vintage, you might be able to boot by (1) in the firmware (BIOS or UEFI?) selecting the “boot from file” option, then (2) browse to \EFI\BOOT\BOOTX64.EFI on Windows PE or Windows Setup media and boot. I haven’t tried this so I don’t know if it will work

          (2) There are different ways to select a boot option. One way is to use a function key (commonly F12) after powering on which brings up a menu from which you can select the system to boot. That might work if Windows Boot Manager is one of the options. That is a one time only boot; it doesn’t change the settings listed in efibootmgr.

          (3) You may be able to set the order of boot choice in the BIOS or UEFI, if there is an entry for Windows Boot Manager. I didn’t see any mention in your postings on this thread that you actually launched the BIOS or UEFI and tried this.

          N.B. if you can select a Windows Boot Manager from either (2) or (3), if it is fouled up, you may get to a grub rescue menu. This will give you a clue that that is (part of) the issue. If it does boot from these techniques, you can use (2) to get to Linux if you ever want/need to use the computer.

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