With the newly released PC Health Check Preview, we now have a better idea why Windows still shows the M1 Mac as incompatible. 1) Parallels claims in https://kb.parallels.com/en/122702#section2 that a TPM Chip isn't required to upgrade to Windows 11 in a virtual machine. "A virtual TPM chip isn't required for upgrading to Windows 11. Starting with Parallels Desktop 17, Parallels Desktop reports to Windows OS that it's running in a virtual environment so that Windows doesn't ask for the presence of a TPM 2.0 chip. " Microsoft seems to disagree, but at least we now have the option to enable TPM, so that shouldn't be a major problem. 2) Apple Silicon isn't on the list of supported processors. This is obviously a huge problem. Parallels and Microsoft need to work something out here. 3) Surprisingly the missing WDDM 2.0 support that many of us thought was causing the incompatibility isn't flagged at all.