1y ago

My "Windows" boot entry has disappeared from the EFI menu

Title. I dual-boot Windows and Linux. I always saw people making "WINDOWS DELETED MY LINUX BOOTLOADER OMGOMG" posts and it had never happened to me. Now, the opposite has happened. I switched from EndeavourOS to OpenSUSE and now my windows install is no longer selectable on boot.

I keep Windows in a separate drive entirely, so instead of using grub, I use the EFI's boot-select menu thingamafuck (look I don't know jargon okay?) to choose Windows when I need it.

Well today it's not there. Only the Linux entries show up. The Windows partition itself seems to be in good order, like, I can access it from within Linux no problem.

But yeah it doesn't show up on my EFI selector thingie. I imagine I could get the EFI Shell going, but I have no idea how to use THAT either.

31 comments

Dual-booting is fine, but this kind of thing does happen.
Either "os-prober" isn't installed or /etc/default/grub has GRUB_DISABLE_OS_PROBER=false.
Fix those, then reinstall the bootloader.
- os-prober was installed, but it was indeed disabled.
  I went through the process of activating it and remaking the grub configuration. But it seems to not care about Windows, likely because, as stated in my post, it is on a separate physical drive. Probably some way to tell it to look there as well, but I don't know it. I might do some searching of my own later, right now I got shit to do. Booted into my laptop (which I keep with just windows because its ssd is too small for me to have any fun)
  
  I dual booted for about two years before switching entirely over to Linux, and I found that using reFind as a bootloader instead of Grub was significantly less hassle. I'd suggest you check it out.
  
  When I dual-boot it is always with a separate drive, less often does MS hose the bootloader in that situation. Normally it is findable. I dont recall havong to point it to anything.
  I keep a usb boot drive with a number of images (ventoy), including "super grub boot disk" to get me out of these situations.
  
  When I dual-boot it is always with a separate drive, less often does MS hose the bootloader in that situation. Normally it is findable. I dont recall havong to point it to anything.
  I keep a usb boot drive with a number of images (ventoy), including "super grub boot disk" to get me out of these situations.
If you have a windows install USB lying around you could try to boot into that and run some commands to restore the EFI entry.
Source 1 Source 2 Source 3
These sources more or less describe the same steps to attempt recovery. The
- The
  Did you get killed mid writing the comment? That's ominous.
  Anyway, I thank you for actual helpful comment instead of the others just calling me dumb for dual booting at all. :P
  I'll see what I can do.
  
  calling me dumb for dual booting at all
  I keep saying this, but Linux users are probably the biggest obstacle standing in the way of Linux adoption.
I FIXED IT
Fucking hell that was a pain. And as most of the painful things in life, it was mostly self-inflicted.
I consider it the polite thing to make a report on what I did to fix things when I solve my problem in a tech support thread (in case someone is ever searching this, to avoid the xkcd scenario ) so I will do that now:
First off, going into a Windows install media and running some commands, as described by @alphapuggle@programming.dev and @Babbiorsetto@lemmy.sdf.org did do the trick for reviving Windows.
BUT, I am an idiot and I pointed Windows to the wrong thing, so it wiped out my Linux boot partition. O o p s i e . . .
I was a bit stumped on what to do, and had actually flashed the USB drive (this idiot here only owns ONE USB drive) with the SUSE install media, fully intending to do a complete reinstall, but THEN,
I realised that in the install media's menu, there is a "boot Linux system" menu, and entered it on a whim
Sure enough, that found my existing OpenSUSE install and let me get into it.
From there I just used YaST to re-install and re-configure grub
Both Windows and Linux seem to be functioning now, yay
So, 85% "me being an idiot", but, the problem is solved. I thank everyone who made a comment.
- Glad it's working! For the future, you might want to put ventoy on your singular USB. You can then put different ISOs on it, so you can have windows and Linux recovery on one keychain. Has saved my ass a number of times!
  
  Oh that's cool
  
  I will probably do that, yes.
Is the windows efi file still in your boot partition or did you format it on install or did you make a new second EFI partition? If you go into your BIOS can it find the EFI file to boot into Windows?
- I did not touch the windows partitions, and that includes the microsoft reserved partition where the windows bootloader (supposedly, linux doesn't let me mount the MSR partition) is.
  I only messed with the drive where Linux was installed and there, I made its own, separate /boot/efi partition.
- But generaly do not dual boot unless you have to.
  Thanks that doesn't help in the slightest :3
Speaking from personal experience.
Do NOT dual-boot, ever.
- Yea so I got no choice?
  
  Seems not. :/
Can you still boot into Windows without GRUB? Like through your bios menu. I've had it where a Linux installer will eat the EFI files for Windows.
If you need to fix your Windows EFI partition, and have a Windows install disk, boot it up and press Shift + F10 to open a command prompt (you may need Fn as well if youre on a laptop)
Run diskpart and list volume
You should have your Windows drive (should be labeled C, but can be mounted elsewhere in recovery. Keep in mind the letter it's mounted on) You're also going to want to look for a fat32 partition. Since windows is on a different drive, there should be two, one for Linux and one for Windows.
Pick one with select volume x where x is the volume number, and ensure you've selected the right one with list disk. There should be an asterisk next to the disk containing the selected volume.
Still in diskpart, you're going to want to mount that to a letter, I always choose N with assign letter n
Type exit to get out of diskpart
Next you're going to want to remove existing EFI files. Type N: to change to the N disk, and rmdir EFI\ /s (I'm doing this from memory, I believe this is the correct command to do so)
To regenerate the files, you're going to want to run bcdboot C:\Windows /s N: /f ALL where C:\Windows is your Windows folder, N: is your efi partition, and ALL is the boot type (this installs both legacy and EFI files, you can set this to just EFI and be fine)
Windows should be good to boot, I'd boot it once to test. Then go into Linux & grub-install and update-grub. It should be able to find it on any installed drive, even unmounted. Check the output and you should see if it found it.
- I cannot get into Windows in any way. I CAN get into Linux with no problem though. Anyway.
  (as I said in my post--) My intention is to not use grub at all and to choose windows through my bios menu when I do need it. Which is what I had been doing for the past year.
  It's just that its entry in the bios menu has disappeared.
  
  In that case, these steps should work, but you can safely ignore the grub steps at the end. (I totally misread the NOT wanting to use grub part lol)

31 comments