Not sure if this is your issue... but...
Being an IT security professional, I follow the same recommended guidelines I implement on the office Windows comps, as on my home Windows comps. i.e. I use a regular "user" account with only "user" privileges for normal computing. The admin account doesn't get used regularly. (Just like on our Linux boxes, we don't use "root," right?

)
So, guess what I'm trying to say is - after I successfully installed G-Force, I ran it for the first time to be presented with a Blank/Black screen with no viz. I had to run G-Force under the "admin" full permission account once, then G-Force wrote it's default configs or whatever... and then I could use G-Force with my normal user account.
But, not everyone is as retarded as me, and most probably just use the default account created with your Windows install (which IS an admin)
just thought I'd point this out, in case anyone was in the same situation...