Need a new motherboard + OS! Help!!!

So I really need a new motherboard for one of my computers. Right now it runs on a p.o.s. AMD Athlon XP 2400+ . . . (1.99gz):cry:

I was looking for a good cheap motherboard and OS. Right now anything will be better then what I am currently using. It should be able to run GW, all HL engine games ( counter strike, TF2...), COD4, Spore, Farcry 2.

HELP ME PLEASE!

before anything do u wana go for amd again or intel atm intel has the market and amd is more of a bang for buck to be frank with u. Wuts ur budget at then we cna go to mobos cpus and other sorts of stuff, also asus does make a good boards i have a 9950 with a K92a its a good board but took me forever to stable 3.0ghz, but on the upside intel has great overclockable cpu's amd does also but not as much as intel so its your decision.