Goto “Start Menu -> All Programs -> Accessories” . Right click on “Command Prompt” and select “Run as Administrator“. If you are not the administrator then you are prompted to enter the password, or else you can proceed to step-2.

2. Now type the following command and hit enter

slmgr -rearm

3. You will be prompted to restart the computer. Once restarted the trial period will be once again reset to 30 days. You can use the above.... Click here to read more