Thats exactly what I am trying to do. But in order to do it I need a working copy of windows inside a VM for me to do the repair ot fresh install.
Reason is I only have access to upgrade disks, over the years I just upgrade from windows version since it makes no sense to pay for a full install disk....however these upgrade disks are capable of full install if they see a working version on the system disk.
In addition even if I want to buy a full install disk for Windows 8 I cannot since they only have oem versions available but that is not acceptable if I wish to move to new hardware which I do when I upgrade my system.
So I'm back to my original plan which is migrate from backups an existing copy of Windows XP, or Windows 7, or current Windows 8 so that I can use the upgrade disk on it to do a clean install.
These backups are available to me as Acronis TIB files, that I can directly convert, or restore to a spare disk and run - then migrate or convert from that.
So far I tested first the conversion with a Windows XP backup I had and it worked fine, although I did have to call the toll free number to reactivate once inside the VM.