Windows Upgrade Help and more

Perfect solution, thanks!

My computer’s TPM is suddenly locked and I can’t access my encrypted drive. I didn’t enter any wrong PINs that I know of. What steps can I take to diagnose the root cause of this lockout so I can prevent it from happening again?

This. Another option is to make sure TPM 2.0 is turned on in your BIOS settings, since that's a hard requirement.

Yeah, You could also try creating a fresh Windows 11 installation USB and using that to do a clean install, as it sometimes bypasses the upgrade block. Hope that helps.