A: It's actually very easy to create a Windows Server 2012 (formerly code-named Windows Server 8) virtual machine (VM) on a file share. When creating the VM, just specify the file share that you've created for the location and that's it! (See screen shot below.)
After creation,the properties will show the file share as the location for the VM and storage. (See screen shot below.)
See FAQs on Windows Server 2012, virtualization, systems management, and all things Microsoft, at John Savill's FAQs.