Parallels Explorer was introduced, which allows the user to browse their Windows system files in Mac OS X without actually launching Windows. A new snapshot feature was included, allowing one to restore their virtual machine environment to a previous state in case of issues. Parallels can run another version of Mac OS X, however due to licensing issues, it will only allow you to run Snow Leopard Server. So you have to trick Parallels into thinking that you are installing a Server Version.
I know the original post regards running an OS X virtual machine in Parallels, but just to clarify:
Windows installed under Parallels (up through version 6, at least) does NOT require a full retail disk.
Mac Os X 10.8 Torrent
I've used Parallels under OS X 10.5.x and 10.6.x, beginning with Parallels Version 3 through 6 (though not Version 7, the latest release), and successfully created Windows virtual machines from OEM Windows XP, Vista, and Windows 7 versions. That does not mean you can use the OEM disks that came with another (HP for example) Windows computer. I purchased the 'vanilla' OEM system disks from a reliable source of computer system components and software, TigerDirect.com
Os X 10 6 8 Download
As I understand it, the only significant difference between OEM and 'full retail' versions of Windows is that OEM disks do not include any Microsoft support. It is assumed that the Original Equipment Manufacturer/system builder provides that support to users. OEM versions are priced significantly cheaper, as a result.