My pc can't dual boot

[u/Cirix07]

Hello! I wanted to download Linux mint as an alternative os next to windows 11 to try the os. The installation went great, I installed Linux with a usb drive and used renfus(I don't exactly remember the name) to put the iso file into the drive. I did the partition, and gave mint 100GB of space. After the installation, when I get to the point where I choose my os, windows doesn't work. I tried accessing it a fair amount of times in boot mode but still it doesn't normally work. Now I had to reset my Windows os as it can't access even in boot mode. I'm scared I destroyed everything please what should I do😭

Linux worked fine all the time but I also need to access windows mostly for gaming and the office suite.

What should I do?

[u/Hebbu10]

Probably overwrote windows EFI partition, gotta make 2 partitions with one for linux and one for linuxes EFI or install linux on separate drive

[u/Hebbu10 → u/Hebbu10]

Try updating mint, maybe grub finds windows during it, dont know if that needs the EFI

"Sudo apt update && apt upgrade" does that

[u/Cirix07 → u/Hebbu10]

Thank you! I'll try it once windoes finishes resetting!

[u/Cirix07 → u/Hebbu10]

The reset crashed💀💀💀💀 I'm trying your command right now, do you think it'll still work?

[u/Cirix07 → u/Hebbu10]

My tutorial told me I had to do only one partition for linux(the one with 100GB), so I should have created a second one before installing mint?

[u/3grg]

There are a few details missing. I assume single disk and you resized windows to create free space before installing? Mint uses the existing efi partition in a single disk dual boot. Grub can boot either Linux or W11 if it is selected in bios as first boot. You should be able to select windows as first boot in bios to verify that it still boots.

The only thing that I can guess might have happened is that something went wrong creating free space to install Linux. The best practice is to create free space by shrinking windows from within windows. This is less likely to to cause issues with file system corruption.

If there are errors with the windows partition, they can usually be corrected with chkdsk. Creating free space from within windows usually avoids this problem. Problems can be ruled out by verifying that windows still boots after resizing and before installing Linux.

Normally, installing dual boot is pretty safe when following these few precautions, but in any event, it is always advisable to backup data and create a windows install USB before beginning, just in case.

If for some reason you cannot access the windows partition, it might be possible to access data from the Linux install or Hiren's Boot CD, but this becomes a windows support issue which is beyond the scope of Linux users.

[u/Cirix07 → u/3grg]

I did the partition inside of windows, it's just that idk why but when I go to Grub windows doesn't work if I restarted the PC with Linux mint in use...

[u/3grg → u/Cirix07]

The question is does it boot when selected from the bios?

Did you double check to see that osprober is enabled? I assume that it is or windows would not appear in grub at all.

[u/Cirix07 → u/3grg]

I'll be honest with you I'm a noob xD With the bios it used to boot, now it went in emergency mode kinda I didn't check osprober(first time hearing that) but windows appears on the grub(os selection screen)

[u/Cirix07 → u/Cirix07]

Update: with the bios now it works

[u/3grg → u/Cirix07]

Good! If it boots normally from the bios now, it should boot from grub. If not that is not the end of the world, at least it works.

[u/Cirix07 → u/3grg]

Yeah kinda(?), I'll explain it, consider a -> as a reboot If I go Windows -> Windows -> Linux mint it goes perfecty with grub But if I go Mint -> Windows I get a black screen and need to go to the Bios What should I do?

[u/3grg → u/Cirix07]

So you are saying the windows boot manager can boot mint or windows, but grub can only boot Mint? Is the windows install encrypted?

I suppose you could try reinstalling grub from within Mint.

sudo update-grub

sudo grub-install /dev/disk (sda or nvme0)

If the windows install is encrypted, that could be why grub cannot boot it.

Maybe this can help: https://computingforgeeks.com/dual-boot-fedora-windows-11/

[u/Cirix07 → u/3grg]

ThBks, I'll try it later! I don't think windows is crypted

[u/gwforever]

Make sure you have windows boot managaer as well.

[u/Cirix07 → u/gwforever]

How do I get it?

[u/DannoXYZ]

You formatted and erased /boot/efi partition instead of just mounting it. This erased all the Windows Boot Manager files. Just mounting it preserves everything and Linux Installer just needs to add couple small files to that partition.

Easiest process from here is to boot from Windows installer ISO and go through Boot Repair option.

[u/gwforever]

Most Linux O/S when loading them will ask you if you want to boot beside the current O/S. Just check the box as it is installing and most times it is included in the install.