Do you need to change your product key so you can activate Windows Vista or Windows 7 properly? You can use a great command line tool that will help you do this very easily. Just follow these steps:

1. Click on the Start Button and type in command prompt so that it shows up on your start menu search list. Right click on the Command Prompt shortcut and select Run As Administrator.
2. At the administrator command prompt, type in "slmgr.vbs -ipk <insert your product key here>"
3. To activate windows after changing the key, run "slmgr.vbs -ato"