I searched the forum for 'DISKPART' and not found so should warn other users of bad experience when I used NGH 15 to clone partitions to a new drive. An old drive had only days to live so I installed a new drive and formatted required partitions. With NGH I made a one off backup to a third healthy drive then used 'Recover Computer' to copy the backup to the partitions on the new drive.
In each case my target drive disappeared completely accompanied by a blue screen and this mucked up the boot loader as well.
Fortunately I was able to boot up the third drive (just a small recovery installation) and could see in diskmgmt.msc that the reason for the blank drive was a conflicting signature. Googling the problem showed I could open cmd as admindistrator and use DISKPART to list the drives and sure enough the target drive had the same ID as the old drive. It is possible to fix this by guessing a new random eight digit hexadecimal number for an ID and that fixed the problem after a restart.