When I play Thing Thing Arena 3 and other games like that my computer lags and freezes, how can I fix this?

Also my computer says I have a low virtual memory, but on any other thing my computer works perfect. I downloaded XP onto a computer that originally had Windows ME on it, could that be causing the problem?|||Virtual Memory is the Windows cache file. It indicates your computer is using your hard drive as emergency RAM. Go to crucial.com, scan your computer, find what type of ram works with it. Get $50, buy at least 1GB and open your comp and install it.