you dont have to pay for steam its a free serive if u bought half-life or anything way back when you just download steam for free and then enter in your cdkey code into steam and then it lets you download and play the steam versions of those games if you havent bought the games before you can go in and purchase them virtually through steam its aquite a nice serve steam is still kinda buggy though but their workin on it and all the cs players are making sure of it
