Hi!
I'm a very old Nero user and one thing I've found about using the Multi-session feature (this may be true of other programs as well) is that there is a max number of times that you can add another session. The disk can get really unstable and even unreadable by some drives.
I take a CD/DVD with me on my service calls, with all my Utility programs on it. I found out that RW and Multi-session disks were unreadable on many of my customers CD/DVD drives.
Nero has always been my favorite CD burning program, but it's become seriously bloated by all the add-on features. I've stopped at version 8 and I use only the "Nero Burning Rom" feature.
For HD backups, there are much better programs, like Ghost and Acronis True Image.
I still use the DOS version of Ghost (Ghost 11.5) for backing up my own HD, whether with XP or Win-7.
It will also back up Linux/Ubuntu.
I can boot it from a flash drive or CD. (the flash drive is the fastest)
Running your backup independent of Windows, like from a boot disk, has many advantages.
Good Luck,
Old Timer
PS: Sorry if I didn't answer your specific question.
I have not, nor will I ever, backup my PC, using the backup program in Windows.