Its good to know that the well known work around to allow Windows Vista to allow it to work for up to 120 days without a serial key will still work on Windows 7. If you happened to forget what the trick was on Windows Vista I have listed the steps required:
First wait for the first 30 days grace period to time out before running this command for the first time.
- Open the start menu
- Type “CMD”
- Right click on the “CMD.exe” and click on “Run As Administrator”
- Type “slmgr –rearm” and press “Enter”
Now you have another 30 days up your sleeve until you have to do your next activation. You are limited to do this 3 times which therefore give you 120 days before your copy of Windows 7 will start to time out.