This article explains volume0 and volume1 when restoring a virtual machine using Select Files/Items option.
You’ve chosen a restore point on your VM, clicked “Next (Select Files/Items)”, created the disk image, and copied the network path into a Windows explorer instance. You now see volume0 and volume1
On Windows 2008 and Windows 2012, volume0 is boot data and volume1 is the VM’s C:\ drive and so forth. Copy the files from the appropriate volume to wherever you need them.
On Windows 2003 the volume0 will be the C:\ drive and other volumes we be labelled accordingly as volume1, volume2, etc.