it's probably scratched or something, so try to clean it (those brush thingies, some spit on a t-shirt, w/e). other than that, dl
daemon tools and see if emulation helps.
as long as you still have the cd-key you should be able to dl it from <insert naughty p2p newtork> and use nero or alcohol 120%. I used to know how to burn war3 using alcohol 120 so if it comes to that just gimme a holla