Microsoft released an update to deal with an issue where you cannot run a Win8-based or WS2012-based virtual machine on W2008 R2 Hyper-V.

Assume that you have the Hyper-V server role installed on a computer that is running Windows Server 2008 R2. You create a virtual machine that is running Windows 8 or Windows Server 2012 on the computer. However, you experience one or more of the following issues:

• The virtual machine stops responding. 
• You receive a Stop error message, and the computer restarts. This behavior stops all running virtual machines together with the computer.

The issue occurs because the Hypervisor does not handle the one-shot synthetic timer correctly.
Note The one-shot synthetic timer is also known as the aperiodic timer.

There is a publicly available update that you can download to resolve this issue.