If you have an existing installation of Hyper-V on Windows Server 2008 that you want to update to Windows Server 2008 R2 beta, this is possible, but you need to be aware of some of the limitations. The first thing you need to be aware of is that we only support upgrading Hyper-V on Windows Server 2008 if you have installed the Hyper-V RTM package on top of Windows Server 2008.  We do not support going straight from Windows Server 2008 with Hyper-V beta to Windows Server 2008 R2 beta.

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