linuxmemes

In my experience (W11 + Fedora on UEFI Thinkpad), I've seen it actually get rid of the Fedora entry from the UEFI boot list. Reinstalling GRUB from chroot didn't fix it, so I used EasyUEFI and manually added the Fedora EFI file to the boot list and that worked.

So it wasn't simply changing the boot order, it actually nuked Fedora from the UEFI boot list.

It sometimes destroys the Linux boot sector too. But it's simple enough to chroot with a live usb and repair it. I don't even have both OS as an option. Mine boots straight into Linux unless I interrupt it and use the boot another drive option. Linux and Windows have their own separate boot sectors, but Windows will fubar the Linux sector randomly.

My guess: the windows update fucked up Grub. Happened to me once or twice in 20 years of dual booting. It is also easily recoverable.

It tends to happen if you are not using the windows bootloader (GRUB for example) but if you use the windows bootloader it should be fine

Same. Never happened to me either. But I usually make a sperate UEFI partition for Linux instead of relying on grub.

I'd argue one shouldn't even be messing with dual booting if they don't understand much about the bootloader.

Windows: "Let me repair Linux for you"

Have you tried first resizing the windows partition inside windows? That's what I did and my dual boot has stayed intact

How can I do that? I'm dual booting but was not aware of this, makes me a little nervous....

If you install Linux first and then Windows on the same drive, it will fuck up your bootloader.

You can easily make Grub boot Windows, so just overwrite whatever fuckup Windows made, or install Windows first.

It won't happen with a simple update, though, that's for sure. Maybe if you're upgrading Windows to a new major release.

But it knows there's a partition there and it's easy to know it's a Linux partition type. Microsoft just prefer to say it doesn't know the partition type and simply say it ignores it. You don't need to have support for a file system in order to check it's partition type. It's just ms bs

Windows likes to mess with the EFI partition on updates, scrweing up bootloaders. That you can prevent by separate EFI partition on another disk, This way Windows doesn't see the other efi files to boot. But when it feesl really obnoxious, it also edits your EFI table and sets itself as the default. That doesn't actually damage your linux boot files, but you still need to log back with some bootstick and revert the change, to make your bootloader/menu the default again.

That's the reason people often switch to Windows only as a VM (there are even solution to passthrough a dedicated graphics card just for Windows, if that's for gaming) after some time. Because Windows is actively working against other OS's on your computer.

In a way their Secure Boot bullshit is nothing different. Get vendors to include MS keys by default, then pretend that Windows is somehow more secure because you need to deactivate Secure Boot to install soemthing else (who cares that one key on every machine is not exactly secure, even more so as MS keys were already found in the wild in malware so they don't even know how to not lose them...)

Whoa.. this really happens?

No, the only thing that windows might do, is reset the bootloader so it skips grub. If you're using UEFI (which you should), you can easily restore it from your bios.

I've only seen it happen on big updates, not the smaller ones.

I unplug physicals disks when installing windows. Learned the hard way when windows placed the boot partition on a device it could not detect the filsystem of. It destroyed my RAID disks (a little but my fault, because I messed up the recovery).

This is what Windows installer saw (going by memory, this was 8 years ago)

• SSD 500 GB (either it recognised ext4 file system, or this one was unknown)
• SSD 500 GB (Where I specified to install windows)
• 4 x HDD 8TB (unknown disks, unknown file system, Windows unaware that this was a RAID-5 software dm-raid)

What did it to? It created a new partition table and wrote data to a new boot partition it made on one of the 8TB disks, no questions asked.

So, to the people who answered you that windows installer cannot do this. Maybe they fixed it. But it certainly could, and it cetianly did. I remember very carefully going through the installer because I was concerned about this happening. I thought about unplugging them, but was lazy. Because "it would be insane for windows to write on a disk it cannot identify the file system of".

Lessons learned:

• If you plan to install windows on a disk along side Linux, install windows first, if you can. Safest bet is still to:
• If you cannot, unplug all other disks other than the one windows is intended to be on.

Edit: I found post on this way back when, but leaving what I wrote as is.

https://superuser.com/questions/758854/mdadm-win7-install-created-a-boot-partition-on-one-of-my-raid6-drives-how-to-r#1243636

I had remembered some details wrong. I had unplugged the Linux SSD, and it wad raid 6 not 5, and it was 2TB disks.

doesn't seem legal

I wouldn't agree here. Even if Windows does do this (which I doubt), there's no way to prove it isn't a bug. And there's no way anyone's going to sue Microsoft over a bug. Not only is that a gross overreaction, it's financial suicide.

If you don't trust Windows, don't use it. Or if you have to, use it on a separate system/drive.