Use Microsoft Windows 7 Free for 120 Days
Microsoft allows anyone to install and use any version of Windows 7 for 30 days without having to enter an activation key. There are no strings attached, and the operating system’s performance is not degraded or defaced during the trial.
There is an easy way you can use Microsoft Windows 7 free for more than the standard trial period. In case you want to Try Windows 7 before you actually buy it you can use it for 120 days and its not illegal because there is a hack present right in Windows 7. You can rearm Windows 7 three times. When the trial expires, use this trick to reactivate Windows 7 to use it more.
Do the following when trial period for Windows 7 expires.
Click Start > All Programs > Accessories > Right-click Command Prompt and choose ‘Run As Administrator’.
Enter your administrator password.
Type the following command and press Enter:
Note the space after slmgr and the hyphen in front of rearm.
Restart Windows 7.
Once the OS restarts, the Properties dialog will indicate that Windows 7’s activation grace period has been reset to a full 30 days.
You can run the -rearm trick a total of three times. If you perform a -rearm at the end of each 30-day period, you end up with 120 days of full, unfettered Windows 7 use without having to supply an activation key in the interim.