HELP ASAP!! Making a copy of a backup.

Okay here is the situation. I've got a backup self boot DC game stored on a 700mb CD and I wanna make a copy of it. I tried copying it onto another 700mb CD on my friends burner which i think is using Nero for burn software. It didnt work. What do I need to make it work ie. any of the downloads on this site. Can anyone tell me what 2 do or direct me 2 something on this site that will help me?

If it's just a simple process. Can some1 guide me thru it step by step as my friend and I are new to copying/backuping CD's.