Clone CD - unable to copy pc dvd game

I am trying to back up a pc dvd game using clone cd. V 5.2 8.1. It seems to read Ok but when i try to write it tells me the dvd is too small to write the file . Any Ideas?

Then use DL.

sorry, new to this what is DL?

Making a working physical copy of a copy protected dvd game that will run without some form of emulation is all but impossible. The best that you can generally do is to make an image from which you can run the game when mounted on a virtual drive.

DL would be Dual Layer (-R DL) and Double Layer (+R DL) media.