Damn XP

What’s up guys. I have a HP pavilion 730n, 2.53ghz, with the standard Gforce4. Recently, I’ve had some connection problems. I’ve got SBC yahoo dsl that I run off a modem so it’s on as soon as my computer is on. When I get to the “internet games” screen for DoD or CS, I can update and refresh just fine. This obviously means that the game is connected to the net. But,when i select a server, it says “connected” and starts “intialzing and downloading” and then disconnects me without any warning. If I try again it takes me out of the game and gives me an XP error report menu. The error report thing is nothing new to me and has happened before but why can I only connect to 1 server out of 300 every time? Help me out guys!
-Tom