|I understand your question.|
You will need a third party program and even then it is not certain that you will recover all or any of it. Here's a free one:
It will give you an idea of the state of your previous information (if any) such as "good" or "poor". I have not personally used this program on a CD but it has worked for files overwritten on the HD.
Note that you have to allocate some other place to restore things to (such as a folder on your hard disk or a USB key drive).
Note also that if it gives a file structure then there are two dots which allow you to move back through the file system to find things.
some other bloke...