Grrrrr, also having problems after coming back to this. Vista x64 SP2, seems that Starforce won't install (get the error about incompatible OS), and it doesnt want to update either. Compatibility mode won't work, nor will running as Administrator.
It's £4.99 on Steam so I'm downloading as we speak - hopefully that'll work.
EDIT: Downloaded from Steam and it runs fine on x64 SP2. Now need to download GWX 3.0, as I've only got 2.0 (although this works too) :p