Arch Linux

Eurkz

Member

Registered: 2021-07-21

Posts: 49

Reinstalled Win10 in my dualboot, now GRUB is gone.

Something similar to this has happened to me before when updating my BIOS, but it was solved by chrooting into the drive and re initializing grub (if i remember correctly).
This time I was having serious game crashing issues in my windows drive so i figured i might as well format the whole drive, and reinstall windows because reinstalling the games wasn't fixing anything. So on that drive I reinstall Win10 (actually Win11, then switched back to Win10 because it was even worse), then restart the computer. I hit the DEL key and change the boot sequence to boot Arch up to see if it will work. My custom grub poped up and i selected Win 10 to see what would happen, says it cant find that disk. I figured maybe its because i didn't update grub yet so now I'm back at the grub menu and select Arch. It boots me into a broken lightDM screen that wont let me do anything so I restart the computer and try again. Now when I'm in the bios there's no GRUB option in the boot sequence. I figure ok i can fix this by chrooting in, so i try that but now every time i boot up the live iso, i select the install medium and it fails with no errors, just black screen and the monitor input starts looping through inputs to find an active input (almost like its failed to post).
I do have CSM Support disabled and secure boot disabled as well.

Does anyone know what my problem is?

Salyman14

Member

Registered: 2021-11-03

Posts: 2

Re: Reinstalled Win10 in my dualboot, now GRUB is gone.

Did the Windows reinstallation wipe the FAT drive where your GRUB bootloader reside?
If not, probably the GRUB bootloader file can be loaded perfectly normally by entering "Boot Device Options" (usually by pressing F9 button).

Did the drive letter of Arch partition change after reinstallation?

AndroGR

Member

From: Athens, Greece.

Registered: 2021-10-15

Posts: 53

Re: Reinstalled Win10 in my dualboot, now GRUB is gone.

Yep, it's gone. Windows overwrites any existing boot options with itself. You will have to get it working again through a chroot of Windows in the terminal.

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Arch | AMD Ryzen 5 1500X | AMD Radeon RX550 4GB | 16GB RAM (3200Mhz) | KDE Plasma | Linux Zen / Custom Kernel

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,296

Re: Reinstalled Win10 in my dualboot, now GRUB is gone.

Windows doesn't do this, your UEFI might. You primarily need to figure out why the live disk isn't booting, have you tried booting with the nomodeset kernel parameter?