Parallels 13, High Sierra, Windows 7Pro on a iMac 5K

I had a VM on an external USB3 SSD drive but when I went to change the video configuration, the machine crashed hard.

Now when I try to restart, I get a black screen asking for a windows install disc
a status 0xc000000e
Info: The boot selection failed because a required device is inaccessible.

I cannot revert to my snapshot, since I am apparently in Rollback mode and have to restart Windows to change the mode.

HELP!

 

Update -
I tried to mount the same VM on another Mac, but got the same error. This Mac has a CD drive, so I could put my Windows CD in. Is there a repair program on the CD that I could use? How would I access it through the Parallels setup interface?

At the moment I am creating a new small VM from the CD in the hopes that I can run a diagnostic / repair from the new VM to fix the larger old VM that crashed.

Any other suggestions?