Why can't I get COD2 to work on multiplayer mode on my computer?

Your system is only worth playing internet based flash games. I sell desktop PC's and I'll tell you straight away that what you're calling a 'new' computer is a 4-year old machine that I sell for $199 brand new. You need a decent video controller for sure. CPU is just about enough, but Sempron is the slowest CPU on the market. Memory is ok... 2GB prefered, everything else is irrelevant. If you live in the States I can hook you up with decent gaming rig that won't break your budget. Thanks