1. Windows XP
Requires activation within 30 days.
After the grace period, core functionality is severely limited:
The system boots but allows only basic operations (e.g., file backup, activation).
Cannot log in normally or use most features until activated.
No automatic shutdown, but the OS becomes effectively unusable.
2. Windows Vista
After 30 days of non-activation, enters Reduced Functionality Mode (RFM).
Key restrictions:
Cannot play Windows games.
Loses premium features (Aero Glass, BitLocker, ReadyBoost).
Automatically logs the user out after 1 hour of use (not a full shutdown, but frequent interruptions).
System remains partially usable but heavily degraded.
3. Windows 7
No automatic shutdown or forced logoff.
After 30 days:
Desktop background turns black every hour (even if changed).
Persistent "This copy of Windows is not genuine" watermark.
Hourly activation reminders.
Only critical security updates are delivered; optional updates blocked.
Otherwise fully functional.
4. Windows 8/8.1
Similar to Windows 7:
Black desktop, watermark, and activation prompts.
No automatic shutdown.
Loss of personalization and optional updates.
Full functionality otherwise preserved.