What happens in this update is that the Virtual Machine configurations are incompatible between Beta and RC0, but only the configurations That’s the catch. The actual virtual disk (.VHD) is still fine, as it’s only a mountable partition. So what you’ll need to do is the following steps:

• After installing Hyper-V RC0, create a NEW virtual machine in the configuration manager
• Use the existing VHD file for the ‘old’ virtual machine on the ‘new’ one.
• Boot the VM!

What you’ll notice after the first boot is that Windows 2008 can no longer control the mouse. This is due to the beta version of the Hyper-V Integration Services being installed on the Virtual Machine. You’re still able to use the keyboard, so if you’re savvy enough to know how to tab around and make your way through Windows, you’ll be able to “Insert Integration Services Setup Disk” in Hyper-V and update the software package

After all this, you should be good to go!

One note is that after I updated to RC0 I had to set back up the network adapter in Hyper-V as it seems my previous network configurations were lost after the upgrade.

Cheers!