May I suggest buying one of the el-cheapo disc cleaner sets you can get from most electronic or gaming stores? They barely cost anything, and there's a decent chance that your disc will be salvagable. Also, look into one of the places that can repair CDs. Most video stores can do that these days, and again it's cheap. As long as there aren't any major scratches you should be able to save it. EDIT: WTF is this thread doing in the RP section, anyways?
As Xiao_Caity said try to clean the disc or just buy a new one (you can get a copy for only 10€). But if you really want to download it, click this link.
Re: My "Arcanum: Of Steamworks and Magic Obscura" For free? Keeping in mind that this is what killed Arcanum, I don't think you'll get much help here. That beeing said, there's always eBay.
Yeah, I'm not even going to click that link. Even with my massive bonuses to internet constitution, I don't think I've got the stamina to handle a goatse marathon today.