Is there any way to test or verify the state of a Windows Complete PC backup, short of actually restoring it to the same machine?
(At the very least, I want to be able to verify that the file system of the backup's virtual disk is healthy.)
Windows Complete PC backup is stored in a VHD format, the VHD file can be mounted in Disk Management in Windows 7, then you can browse the files, this is not a full blown verification but is all you can do since Windows has no verification tool.
Once the VHD is mounted it will show up in Explorer with a Drive letter, if you cannot browse the new drive then most likely the image is corrupt. You can then Detach the VHD in disk management in the lower right pane of disk management by right clicking on the small space next to the volume (Disk 3 in my case).
Vista or XP you will have to install a component of Virtual Server to mount a VHD file http://www.tech-recipes.com/rx/3595/windows-xpvista-how-to-attach-a-vhd-file/