Please keep your reply in the same thread, so wen can follow the communication.

Did you check the manufactures website?
What is the Brand and Model number of your computer.

Also if you don't want to re-install Vista ( I would recommend a re-install though) you can change your current license to a valid one.
Click the logo to open the start menu, right click on Computer and choose Properties.
On the bottom of the system properties screen, there is a Windows Activation section with a link to change your product key.