I wish I had found this thread a couple of weeks earlier than I just did. I have exactly the same card in one of my machines. Mine has 128MB of memory, not sure about yours. Scores 1.0 in Vista! (because of no WDDM driver). With a WDDM driver, it should get a 1.5 or nearly a 2.0. That card is very good with 2d graphics and direct x 7 and 8 are very good with that card too.
Actually, now I think of it, I think I have the 4600 as mine is a bit longer I think.
If I was you, I would undo those tiny screws on the fan cover and clean out the dust in that card. I did the same with mine (had slightly more dusty than yours) and it helped the card so much. I got at least a 10 fps increase with the temps a couple of degrees c lower too.