I'm trying to switch from Windows 11 to Linux and chose CachyOS as my first distribution. I created a bootable USB and erased my SSDs, but every installation attempt stops with the error "Failed to install bootloader." Secure Boot is already disabled, and I've tried several suggestions with friends without success. The installer logs show that grub-install exits with an error and reports: "EFI variables are not supported on this system." I'm not sure whether the problem is my partition layout, the USB, or the way the installer was booted. What should I check or change so CachyOS can install and boot correctly?
3 Answers
Since the drives have already been wiped, a clean automatic install is worth trying. From the live environment, open GParted, delete every existing partition, apply the changes, and confirm the drive shows as completely unallocated. Then restart the CachyOS installer and let it create the GPT and EFI partitions automatically. If it still fails, recreate the live USB and verify the downloaded ISO before trying again.
This can also happen when the firmware refuses to create EFI entries. If the files were installed successfully, check the firmware’s boot options for “Boot from file” or a way to add a boot entry manually, then select the CachyOS GRUB or shim EFI file on the EFI partition. Another option is to boot the installed system from the live USB, chroot into it, reinstall GRUB, and use the removable fallback option if normal EFI registration keeps failing.
Secure Boot was one of the first things I disabled, so that part should already be covered. I’ll check whether the USB was started in legacy mode and look for a manual EFI boot option.
The log strongly suggests that the live USB was booted in legacy BIOS/CSM mode instead of UEFI mode. In that mode, the installer can’t access the system’s EFI variables, so it can’t create a UEFI boot entry. Reboot and use your firmware’s one-time boot menu to select the USB entry explicitly labeled UEFI. Also disable CSM or legacy boot support if your firmware has that option, then run the installer again.
Manual partitions were my first attempt, but I wasn’t sure whether creating or deleting them from GParted would make a difference. I’ll try clearing the disk first and using the automatic layout.