If he is running Window 11, from a PC that was made circa 2011, he has bypassed all Win11 installation requirements, so nothing should be assumed.
In Windows, start PowerShell in Administrative Mode
Code:
Select-String "Detected boot environment" C:/Windows/Panther/setupact.log
That will return the Boot mode Windows was booted in...
And fastboot can be turned off while still in Powershell