Windows 8.1 HyperV notes
Hyper-V is a Feature you must install.
Hyper-V has no import of Vmware vm's unless they reside on a esx host.
You cannot import a vm from an image backup -- it must be the same hardware.
The only way I could find to import the vm's was to convert the disk image with winimage.
Hyper-V only has 4:3 video aspect ratio and fixed resolutions, because of this I run the vm's in RDP.
See http://ittechlog.wordpress.com/2012/09/11/converting-a-vmdk-to-vhd-with-microsoft-virtual-machine-converter-mvmc/ for Microsoft's converter
Hyper-V does mount and boot any bootable disk. You can run each vm on its own disk (much faster).
You can install Windows 8.1 on a new disk and then run your old image as a vm with no problem.