Rearming your Windows 7 will let it run freely for 120 days without activation
@ 2009/08/21Like Windows Vista, the upcoming Windows 7 comes with a command line utility called the Software License Manager (slmgr.exe) that allows the user to issue "-rearm" switch that will reset the countdown timer back to 30 days. This command may be issued a maximum of three times. If a user issues this command at the end of each 30-day period for three times, he or she would be able to use Windows 7 unrestricted for up to 120 days.
The procedure to reset the countdown is identical to the process used for Windows Vista:
The procedure to reset the countdown is identical to the process used for Windows Vista:
1. Start the command line by clicking Start > All Programs > Accessories > Command Prompt (Run As Administrator) – or for a shortcut, hit the Windows Key + R and type "cmd".After the reboot, your counter will have reset back the 30 days.
2. At the command line, enter in "slmgr –rearm" without the quotations.
3. Restart Windows 7.