If I correctly understand what you're asking, TK, the Windows Genuine Advantage Validation Tool will be intalled automatically when you visit
Windows Update
Oh, and Windows Update will work only with M$ browsers - 3rd Party browsers are not supported. You can configure Firefox to open specific pages in IE if you wish, but its just as easy to sinmply use IE for your visits to Windows Update.
Just FYI - In versions of Windows previous to XP, the product key is relatively easy to dig out of the registry if you know where to look. With XP, not so; the key is there, but encrypted.
ViewKeyXP and
Magical Jellybean[/i][/u] are free utitlities which will unencrypt and report your Windows product key.