Thanks for the insight. What kind of card would you suggest and do you think the rest of my system is acceptable?
Depends on your budget, motherboard and what you intend to play with it.
Is the Quadro a PCIE card? If it's AGP then that means your motherboard won't take a modern card as AGP is old technology now. I'm sure I saw the FX Quadro was PCIE but you need to make sure.
If you are going to only play F4 BMS an AF and are on a budget then look at the NVIDIA GTX 550 Series as that exceeds the 'it rocks on' requirement on the BMS site
http://www.benchmarksims.org/forum/content.php?132 and is pretty cheap with a 2Gb version at £149
HERE but start at around £35. Or a GTX 560 starts from around £120 up to over £200.
I don't know anything about your CPU though so can't comment on how it stacks up against the specs list on the BMS site. 4Gb is the most WinXP will recognise so nothing to improve there.