Heyyo,
This'll be hard to explain, and not to piss off pmb...
Ok, the problem is, they shut down the won master servers eh? so in order to play it, you have to find a new won master server. but that would require changing files that are as whistler pointed out, "restricted."
Pretty ghey eh? I say, pre-steam is now abandonware since they shut down all official won master servers, and no longer support it... but just cause it's fact and an opinion doesn't make it so.