Early adopters playing around with the Developer Preview of Windows 8 have undoubtedly come across a few issues when attempting to deploy the platform as a guest OS in a virtual machine running in a virtualization solution from Microsoft.
The first public taste of the next iteration of Windows is still in the Milestone 3 (M3) stage of the development process, and as such, various issues, including incompatibility problems, are to be expected.
Fact is that Windows 8 Developer Preview Build 8102 M3 is incompatible with a few virtualization solutions, including two of Microsoft’s own products: Windows Virtual PC or on Microsoft Virtual PC 2007.
Windows 8 Doesn?t Support Windows Virtual PC or Virtual PC 2007 - Softpedia