Assuming it IS a problem with the media, the first thing I'd try is copying the whole CD to your hard drive an installing from there. If that does't work, you could take it back to the store where you bought it and exchange it for a new copy. If you don't mind a huge download, you could try registering the game on Stardock Central (https://www.stardock.com/products/sdcentral/) and then downloading the whole thing from there. I don't know what registering that particular media will do for the "returnability" of those disks, though.