Are you looking to change your Windows Vista product key in order to activate Windows Vista? There are two simple ways you can do this. You can easily change your Vista product key via the shortcut in the System menu or you could use the command line tool to do this very quickly. In the following simple solution, I cover both approaches.
Changing Windows Vista Product key (graphically):
Click Start > Control Panel, then click System and Maintenance and then System.
At the bottom of the System window, click the option to Change product key:
You are now presented with the ability to change the product key. Enter your new Windows Vista Product Key and click Next:
Changing Windows Vista Product key (Command Line):
Click Start > All Programs > Accessories. Right click on Command Prompt and choose to Run as administrator.
From the command line, type slmgr.vbs -ipk KEY replacing KEY with your actual product key, then press Enter.
To activate Windows Vista after changing your product key, type slmgr.vbs -ato