If the host is intended to be used as a Hyper-V host, download and install the released version of Hyper-V (KB950050) from ...

1) If the host is intended to be used as a Hyper-V host, download and install the released version of Hyper-V (KB950050) from http://go.microsoft.com/fwlink/?LinkId=142900, and then download and install Hyper-V update (KB956589) from http://go.microsoft.com/fwlink/?LinkID=113199. If you are not sure whether the host has hardware-assisted virtualization support or whether it is enabled in the BIOS, download the Virtualization Detect (DetectVp.EXE) tool and run it on the host to confirm that it meets the requirements. To download the tool as part of the Windows Logo Kit (WLK), go to http://go.microsoft.com/fwlink/?LinkId=121104.
2) If the host is intended to be used as a Virtual Server host, download and install Virtual Server 2005 R2 SP1 and the latest update on the host. To download Virtual Server 2005 R2 SP1, go to http://go.microsoft.com/fwlink/?LinkID=120488. To download the latest update, go to http://go.microsoft.com/fwlink/?LinkId=121055.