A simple msdn blog post on how to mount a .vhd file in windows 7 using the disk management utility. Link Removed
Sounds to me like under your current boot scenario "System Repair Disk", that you network components are not supported. So unless you have a means to attach the drive containing your systems images locally (USB) or can somehow move or copy them to a local drive or partition, then you may have to reinstall Windows 7 to a point where your computer can access your network in order to be able to use those images on your NAS and then perform the image recovery.
Regards
Randy