I'd been running SCVVM Beta 2. It was throwing some errors and I didn't need the functionality anymore, so I uninstalled it. After I did that, when I'd try to connect to VMs from Hyper-V manager, I was getting the following error.

"A connection will not be made because credentials may not be sent to the remote computer. For assistance, contact your system administrator."

The following directions will fix it.

http://social.technet.microsoft.com/Forums/en-US/winserverhyperv/thread/ce6a9d04-45bf-4d77-869e-bbf784cbefd1/