Today Saturday i found some time to continue to install my Learning Server with Windows Server 2008 R2. After i installed Windows Sever 2008 R2 i added the Hyper-V role.

I have a Intel-Core-i7-2600K-Processor in my ASUS board. After turning on the Virtualization Technology in the BOIS i started the Server and wanted to start a Virtual Machine i got a error message

An error occurred while attempting to start the selected virtual machine(s).
 could not initialize

Also, an Event 3040 is logged in the Hyper-V-Worker node under Applications and Services Logs that contains an error message that resembles the following:

 Failed to set/change partition property

The problem is that the new Intel Processor introduces support for the AVX feature in the Sandy Bridge processor family.

The solution is to upgrade to SP1

Source for solution Microsoft Solution Center
Use Hotfix if you dont want to upgarde to SP1