What's the Windows Vista reduced functionality mode?
If Vista (and Windows Server "Longhorn," codename for the next Windows Server
version) isn't activated within 30 days after installation for the retail release
of Vista or within three days of changing a major hardware component, the built-in
Windows Genuine Advantage (WGA) feature will place the computer in out-of-grace
reduced functionality mode, which will allow access to Vista for a period
of one hour. During that one hour, you can perform most functions, including:
You can't run any of the built-in games or run premium features such as the
Aero UI, Windows ReadyBoost, or BitLocker Drive Encryption. If you attempt to
log on when Vista is in reduced functionality mode, you'll receive the message:
Activate Windows Now. Your activation period has expired and Windows is no
longer working. To use Windows you must activate this copy of Windows.
—John Savill