General Discussions

[charles4691]

Hey guys, I am stumped on this. I have a MSI X570 Unify with a Ryzen 3900X and I wanted to move to windows 11. I checked my settings, and all was good, used the PC health check to make sure all was good. It said I was able to update to windows 11, great. So, I did a clean install, and everything was good to go. I really like windows 11, but after about 3 weeks in I got a message saying that my system no longer supported windows 11. It seems my settings in the bios went from CSM to LEGACY mode. So, I switched back to CSM but when I went to exit the bios, it rebooted back into bios. The only way I could get back to the desktop was to have it in legacy mode. I went a good 3 weeks with windows 11 and everything was fantastic. Does anyone here have any idea to what may have happened for this to happened? I am using bios version   7C35vAB. Which allows support for Windows 11. Thanks for any help with this. Have a great day!

[elstaci · Accepted solution]

That is your problem is that you can't have CSM Mode enabled in BIOS.

CSM Mode is Legacy mode. You need to disable CSM Mode and enable UEFI Mode strictly.

On some motherboards like my Asus Motherboard when I disable CSM Mode I lose video output until Windows starts to load but depends on the monitor you have.

Also if you have some installed hardware that requires CSM Mode for it to work than you will have problems with that legacy hardware.

If BIOS won't allow you to enable UEFI Mode is probably due to some hardware you have installed that requires CSM/Legacy Mode to be enabled. just guessing though.

Do you have fTPM or TPM enabled in BIOS?

NOTE: Could also be your BIOS got corrupted. Try re-flashing the BIOS again and see if it boots into Windows 11 Desktop again.

EDIT: From your Asus Motherboard Manual concerning BIOS Settigns: