I have attempted to install Mint 22.3 on my old laptop (Lenovo Yoga C930) which was previously running Windows 11 and seem to have no operating system present on the laptop now and can not boot from my USB drive.
I started by downloading Mint 22.3 “Zena” on to a USB drive via Rufus, booted into Mint via the BiOS, and attempted to “Erase Disk and Install Linux Mint” by following the prompts. The install process gave some error messages as it proceeded and took significantly longer than the help videos I had watched beforehand suggested. I left it running over night and came back to it still attempting to install in the morning.
I pressed the power button on the laptop to stop it and when I turned it back on was met with a message along the lines of “remove bootable drive”. The next message I got was “Default Boot Device Missing or Boot Failed”, I hit OK and now there appears to be no OS on the Boot Manager.
When I put the bootable USB back in, the boot manager finds it but when I select it I receive: Failed to open \EFI\BOOT\mmx64.efi - Not Found Failed to load image (blank square): Not Found Failed to start MokManager: Not Found Something has gone seriously wrong: import_mok_state() failed: Not Found
This is my first time attempting to install an operating system so I really am not sure what went wrong or where to go from here, any help would be greatly appreciated.
Edit: successful install! Thank you very much to everyone who took the time to help me out with this :)


Thats the boot manager not the BIOS? You need to go into the BIOS to disable secure boot. You need to press F2 immediately on restart. The BIOS has many more options including disabling secure boot and setting up a default boot order
The boot manager is accessed via F12 and only shows you available devices to boot based on the rules in the BIOS.
I installed Linux (Opensuse) on a Lenovo Yoga recently. I disabled secure boot prior to install and enabled USB boot to get the installer running.
Your linux install failed as it didnt complete so its best to reinstall completely, and I agree with the prior poster: use balena etcher to make a fresh USB stick and verify the ISO is intact. Or Ventoy is a good tool to set up a USB stick with too - you can drop isos onto a USB stick and pick whichever one you want to boot from. But if using ventoy, still.manually verify the downloaded Mint ISO matches the original online file using the provided SHA on its download page.
Thank you for clarifying that, I did not realize I was not in the BIOS menu there (very inexperienced at tinkering with computers as you can tell)
I validated the ISO and downloaded balena. Flashing the USB drive now and will try that out.