Do you need to change your product key so you can activate Windows Vista, Windows 7 or Windows 8 properly? You can use a great command line tool that will help you do this very quickly. Just follow these steps:
- Launch the Start Menu and type in command prompt or cmd so that it shows up on your start menu search list. Right click on the Command Prompt shortcut and select Run As Administrator.
- At the administrator command prompt, type in "slmgr.vbs -ipk <insert your product key here>"
slmgr.vbs -ipk 00000-00000-00000-00000-00000
- To activate windows after changing the key, run "slmgr.vbs -ato"
Alternatively, if you want to use a graphical interface, run the following at a command prompt as suggested by Dave in the comments.
Then just type in your product key and click the Activate button.