Windows with High Precision Event Timer (HPET)
I installed windows 7 with HPET disabled in BIOS.

Then if you do:
bcdedit /set useplatformclock true -> with HPET enabled windows won't boot
bcdedit /deletevalue useplatformclock -> disables HPET from an administrative cmd console

When HPET is enabled in BIOS but disabled in Window then Windows will move slower than usual.