Star Wars Old Republic requires a GDDR3 graphic card minimum
Your GDDR2 is outdated for this game
If you take a look on my topic here:
http://www.computerhope.com/forum/index.php/topic,127386.0/all.htmlI just upgraded my graphic card... you'll have a good idea.
It depend on your budget, but you should get a 1GB GDDR5 graphic card. And the cheapest one is the nVidia GT440. Or the ATI Radeon 6770
XFX makes good ATi Radeon graphic cards (according to RAPTOR), and ASUS makes good nVidia graphic cards.
They both should be compatible with your computer. But to make sure, you HAVE to give your motherboard model
But if you have an 8GB RAM, and a 64bits operating system, that's more likely that your motherboard is compatible with PCI express 2.0
But upgrading that Graphic card, means that you have to get a 600W power supply