I'm trying to switch from Windows 11 to Linux and chose CachyOS as my first distribution. I created a bootable USB and erased the SSDs, but every installation attempt ends with "Failed to install bootloader." I've already tried disabling Secure Boot and several other fixes, but nothing has worked. The installer logs show `grub-install` failing with "EFI variables are not supported on this system." What should I check or change to get the system installed?
3 Answers
Some firmware refuses to create EFI boot entries even when the installation itself is correct. If the files were placed on the EFI partition, try using the firmware’s “Boot from file” option and select `EFI/ CachyOS/grubx64.efi` or the corresponding `shimx64.efi` file. Another option is to boot the live environment, chroot into the installed system, reinstall GRUB, and add `--removable` to the `grub-install` command so it uses the fallback boot path.
The log strongly suggests the live USB was booted in legacy BIOS/CSM mode instead of UEFI mode. In that mode, the installer cannot access the EFI variables needed to create a boot entry. Reboot into the firmware boot menu and choose the USB entry that is explicitly labeled UEFI. Also check the firmware settings and disable Legacy Boot or CSM if enabled. Once the installer is running in UEFI mode, the bootloader should install normally.
It may also be worth starting over with a clean partition table. From the live USB, open GParted, delete every partition on the target SSD, apply the changes, and then let the CachyOS installer create the partitions automatically. If the USB image might be corrupted, recreate it and verify the ISO checksum first.
I tried creating partitions manually in the installer, but I hadn’t tested wiping the drive completely from GParted. I’ll also recreate the USB and make sure the machine is booted through its UEFI entry.