If you ever need to change your Vista product key, rest assured you can do so without having to reinstall the operating system. There is a command line tool included with Vista that lets you type in a new product key.

To change your Vista product key:

1. Click on the Start Button and type Command Prompt in the search field.
2. From the list that appears, right click the Command Prompt shortcut and select Run As Administrator.
3. At the administrator command prompt, type in “slmgr.vbs -ipk [insert your product key here]”
4. To activate windows after changing the key, run “slmgr.vbs -ato”