I am dual booting windows and Linux. They are on seperate drives and have had zero issues for the last 2 years. A few days ago I decided to update to the latest version of Linux Mint and had no problems, I think the grub screen was still good after a restart (can't totally be sure if I chose windows from grub screen or it went right to windows). Then a day later, I decided to finally upgrade to windows 11 (I hadn't before because I was afraid it would bork something), and here we are. Now I have no grub screen, and can't boot my Linux drive. I did a fair amount of research and I understand boot orders get messed up in BIOS after updates sometimes, or you can' even see boot drive at all. This is not the case. I Bios I can see drive, boot order is correct. When I go directly to boot menu and select Linux drive it just blinks my screen and stays in Bios, does nothing. Click on windows from there and it boots fine. I'm guessing my boot partition is messed up. My question is, How can I fix this without having to reinstall Linux. Is it even possible. I should mention that I am not a linux pro, but I'm not a newbie either. On a scale of 1 to 10, I'd say I'm a 5, maybe 6. I really only use Linux for coding these days.
shimx64.efifile in the ESP with theshimx64.efi.signedfile from here. IIRC you can go into Disk Management in Windows and temporarily assign a drive letter to the ESP, that should give you easy access.