What make/model pc is it? Have you tried temporarily repairing the scratches so you can at least make a usable copy of it?
If you have a Dell pc, you can get replacement CD's easily enough...often times free for the asking. I've actually done this a few times with Dell, and they even do free overnight shipping.
I had to reload windows and had trouble with my old oem disk loading. to scrached up. I asked the IT guy at work for a copy. He gave me a copy with another key code. I ask him where the key code came from and he said it was the company keycode. I deleated my drive with killdisk and loaded windows. When I tried to update windows it said it wasnt a genuine copy. I called him and asked him where he got the keycode and he said, a friend. I knew it then it was a crack code. I was mad because I have a legal code and I told him I did before I got the copy. Anyway I used kill disk again and tried to reload windows nad nothing happens except the blue screen and starting windows. Nothing loads on the bottom of the screen.Ive tried everything, cleared cmos, updated bios, ran kill disk, and it still wont work. I think microsoft installed a bug since it was a legal key code.