U CAN EXTEND WINDOWS 7 TRIAL FROM 30 DAYS TO 120 DAYS

You know, Windows 7 is free for 30 days trial usage. now you can extend its trial usage to maximum of 120 days without any key.

Click here to download the trial of Windows 7 from Softpedia

The Steps to do are given here,

• Go to "My Computer" (Computer) , then  right click the mouse at any blank space & select properties, here you can see the number of days remaining for the trial version.
  
• Make sure that only one day is left for end of trial version
• Then go to Start--> Right click on Command Prompt & select Run as administrator.

• Then the command prompt will show like this "C:\Windows\System32>"
• You just type this command to that "slmgr -rearm" 
•  like this "C:\Windows\System32>slmgr -rearm"
• After  that, there will be a dialog saying Command completed successfully
• Now check the system. It will show the trial period remaining as 30days. Do this process whenever your trial gets over.