Windows Upgrade Help and more

Agreed, that troubleshooter is a good first step. Also, double-checking for any pending Windows updates can help lock those settings in place.

Same here. You could also try running the Windows Update troubleshooter, as that specific error code can sometimes be linked to update components.

You could also explore using the Windows App SDK with WinUI 3 controls, which are built to directly reflect the latest system design. Hope that helps.

+1 You could also check if your motherboard has a TPM header and consider adding a discrete TPM module. Another option is to look into a registry edit workaround, though that's not officially supported. Hope that helps.

Yeah, and sometimes you need to switch from CSM/Legacy boot to UEFI mode for Secure Boot to even show up as an option.