(http://www.blogsdna.com/wp-content/uploads/2008/06/windows-vienna-7-logo.png)
In case you need to change product key of windows 7 and don’t know how to do it then here is small guide for how to change windows 7 product key.
How to Change windows 7 Product key
Method 1: Manual
1. Right Click on My Computer and Select Properties.
2. Wait a second for windows activation details to get populated.
3. Click on Change Product key link after your Windows 7 activation details are populated.
(http://www.blogsdna.com/wp-content/uploads/2009/01/change-windows-7-product-key.png)
4. Enter New Product Key and click on next to activate your windows 7
(http://www.blogsdna.com/wp-content/uploads/2009/01/enter-product-key.png)
Method 2: Command Prompt
1. Click on start and type command (cmd) with run as administrator option or check how to open elevated command prompt
2. Now type following command
“slmgr.vbs -ipk <insert your new product key here>”
3. To activate windows after changing the key, run “slmgr.vbs -ato”
(http://www.blogsdna.com/wp-content/uploads/2009/01/command-prompt-change-windows-7-prodcut-key.png)