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.
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.
I believe the Windows utilities will be better than any third party software. But some third parties, like Acronis do have options the Windows Backup utility does not when it comes to the configuration of your hard drive.
Both utilities will make a backup image of your drive and file backups, but the Windows one is free..