I really hope this does something as i have no other ideas at the moment.
I'm not 100 percent sure this will work, but i go by the rule that anything is worth a shot After these are installed, i would just load up fallout 3 and see if you can clicked the button then. This should download the client, the marketplace, as well as the sign in assistant and i believe that the sign in assistant is what you need. If you're the type of person who is really 'virus paranoid' and don't trust me giving you a direct link to a download, then just search 'GFWL update' on google and hit the first link. Okay, so i'm not sure if this is the GFWL program you were talking about, but here is a link to what i think you should download.