No files on DVD?


I have a problem with a DVD from a friend. He burned a DVD-RW.
The DVD works at his computer for nearly 3 month. Now he cant read the DVD, and gave it to me, and hope I can read the files, but I can´t!
I tried CDroller, blindwrite, nero, cloneDVD, but there is only one result: “no disk in the drive”.

Is ther anyone who can help me?
What software could I use?
I think I need a program, which tries to read the DVD, without checking for a DVD in the Drive.