HelpWindows7.com

[ian]

Is there any way to use windows 7 without any key and to extend its trial mode to 120 days?

[duncan]

Here are some steps
(1)Install Windows 7 without any product activation key.
(2)Once installation is completed, use the Windows 7 for 30 days and wait for the remaining days left to activate Windows counting down to 0.
When the activation grace period is ended, log on to Windows 7 desktop, and open a Command Prompt window and type any of the following commands into the command prompt, and then hit Enter:
sysprep /generalize

slmgr.vbs –rearm

rundll32 slc.dll,SLReArmWindows

slmgr /rearm

Reboot Windows 7 to enjoy another 30 days of free usage.

You can run the rearm command for max of 3 times.