Error "Windows cannot access the installation sources. Verify that the installation sources are accessible, and restart the installation"

It's logical to assume that when you build Hyper-V virtual machines to use the Windows media that came shipped with the hardware??

The VM boots from the either the ISO or the DVD media fine, but then issues this error:

"Windows cannot access the installation sources. Verify that the installation sources are accessible, and restart the installation"

Luckily I also had a non OEM copy of 2012, which works a treat!!  Looks like you can't use Dell OEM media to build virtual machines.

If you don't have a copy, you will need to download it from the volume licensing center https://www.microsoft.com/Licensing/servicecenter/default.aspx or apply for the Windows 2012 server trial.

This can also be caused by a damaged or corrupt VHX/VHDX