I've got that same stupid built-in card in mine. Don't forget to factor in the price of a power supply if your current build has less than a 500W. I was thinking of getting a GeForce 9800GT as an upgrade, but I'm no expert.
STAR TREK ONLINE Our ongoing Mission:
--> To constantly seek better ships
--> To acquire and upgrade bigger weapons
--> To boldly grind what everyone has ground before.
Sorry to burst your bubble but your going to need something stronger then even my HD4890 to fully max out STO with no hicups. I'd look into a 750Watt PSU and an HD7870 or GTX660Ti, that'll set you up for a good while. An I mention the PSU cause in a pre-made PC they always max out the PSU regardless of what is in the PC to save money.