Need assistance? The Windows 10 installation vanished from the boot menu.
Need assistance? The Windows 10 installation vanished from the boot menu.
I worry that my dualboot configuration might be damaged, which worked well before. Recently I added an empty disk to test a fresh Windows installation on it, intending to use it elsewhere. During the USB installation it slowed down significantly, displaying a black screen and making me think it was stuck. Frustrated, I rebooted several times. It seems this was the point where things went wrong. Now I can’t boot into Windows at all. I’ve noticed error messages in Grub like “no such device” and “unknown filesystem.” The Windows entry is missing from both the Grub menu and the BIOS boot order list.
I’m glad I can still access my Linux system and retrieve my Windows files from there. Gparted lists the Windows partition (the C:/ drive) but warns about a “Microsoft reserved partition,” which I assume is necessary for booting. Could you assist in resolving this issue?
I understand. Please accept my apologies if it seems like a simple mistake.
Yes, I used a system that didn't have a harddisk, so I connected the empty disk to my workstation and started the process, intending to later swap it out for the one with a harddisk and finish.
Here’s a revised version of your text:
Hi, this should assist in reinstating your Windows dual boot setup.
Repair Bootloader via Command Prompt
Utilize DiskPart to locate the drives:
Enter diskpart and press Enter.
Enter list vol to display all volumes and pinpoint the drive letter for your Windows installation (such as C) and your EFI system partition (commonly a small FAT32 drive).
If your EFI partition lacks a letter, choose it using select volume X (with X being its index) and assign it with assign letter=G.
Execute exit to close DiskPart.
Run bootrec /fixboot (creates a fresh boot sector)
Run bootrec /rebuildbcd (detects Windows installations and adds them to the Boot Configuration Data)
For EFI systems, use bcdboot:
If you have an EFI system, execute the following command, substituting G: with your EFI partition’s drive letter and C: with your Windows partition’s letter:
bcdboot C:\Windows /l en-us /s G: /f ALL
Once completed, restart your computer. The dual-boot interface should reappear or Windows should launch properly.
Thank you for your response. It assisted me in re-establishing connection with Windows, though not perfectly as intended. For your reference, here’s what I did:
- Accessed the Command Prompt via a bootable Windows USB, proceeded through the install steps, and selected "Repair your computer."
- Followed the initial instructions to run "diskpart" and completed the first four steps.
- After step 5, encountered an error stating "access denied," exited the command prompt.
- Chose to continue to Windows, but it failed to boot, displaying "disk 'xxx,xxx' not found." I pressed Esc to return to the grub menu.
- In the grub interface, I again pressed Esc to navigate to another screen, where I typed "exit" to proceed and successfully booted normally.
To be truthful, I’m uncertain if your instructions made a noticeable impact, or if avoiding the grub error was an indirect way of returning to Windows despite difficulties.
Currently, the problem remains: I cannot select Windows from the grub menu at startup. It seems there’s an issue with the connection between the boot options and the operating systems.