How do i make a copy of CoD4?

Okay I have CoD4, but it has like a pretty bad scratch and it wont install a file during the installation process.

So i was wondering, would i be able to make a copy of it and use that instead of my original?

Or will the copy of the game still have the same error?

And of all, you guys know any ways to clean scratches or where i can take the game to stores that have cd cleaners?

Thanks.

you can try using a disc repairer which wears down the out surface till the scratch is gone, discs have quite a thick layer that can be removed safely, or if you are cheap you can just use some toothpaste or rub that on it to wear it down.