Hi thankyou for reply the game i want to back up is "command & conquer tiberium wars" i wish to make a working backup can this be done ?.Not quite the same but somebody did a bioshock dvd9 to a dvd5, so if thats the game you have your in luck, otherwise i dont think its feasible.
But if its for backup purposes only you could make a multi volume rar archive(with recovery record just i case) Or a multi volume 7zip archive(no recovery option, but you could use quickpar or similar)
Bioshock DVD9 to a SINGLE DVD5
http://fileforums.com/showthread.php?t=81767&highlight=Command