I'm not sure if you can run it, but I'd suggest getting the Orange Box. There's no way in hell you'll be able to run Team Fortress 2, but you might be able to run Half Life 2, which has a great single player campaign and will also get you access to a plethora of free mods.
http://www.systemrequirementslab.com/referrer/srtest
Check to see if you can run it.






