Need help making back-up for Diablo II

[Willy]

I made a back-up using clonecd for all 3 discs (english ver.) and when i try to play the game it says insert play disc in drive.. After i do that i cliick on "OK" then it pops up the same screen...(insert disc in drive) So my question is how do I make a back up copy of my game? Do I have to reconfigure my clonecd settings when i copy it?
Any advice will be helpful thanks..