I have your answer for you.
Upgrading to one gig of ram will help, but not dramatically solve your problem. Your problem is with the graphics card, both in the low bus of the PCI regular slot and of the GPU...graphics processing units. Game speed is dependent upon three factors, sometimes four: processor speed, RAM speed, hard drive speed (RPM), and FSB. If one of these is slow, it can pull down game performance. If one or two are slow, then game performance really suffers. The best thing that you could do would be to upgrade to a better GPU graphics card, but finding a newer one that will run in a regular PCI slot is going to be difficult. I suggest save up and go for the totally new upgrade of Motherboard, RAM, processor, and Graphics card, but this is not the answer for everyone...or their wallets. Mine included. If you want to look for a new graphics card, try
www.newegg.com