Windows Genuine Advantage Plug-in?

The only thing to be aware of, is that you could have your install of Windows crippled if WGA hits a false positive and decides your legit copy is not "genuine". This would usually involve annoying banner instructing you to buy another copy of Windows. They do have a support forum here if you run into this down the road. Microsoft has also introduced this for MS Office 2003, so I would keep that in mind before you update Office. Further information about WGA can be found here

But this won't be nearly as bad as Vista WGA, which will severely cripple your installation at any time, limiting your session to minutes and only allowing IE to run if it suddenly decides your license isn't legit (it will revalidate on a regular basis.)

Jam it back in, in the dark.