Default credentials not being saved in Hyper-V Manager for a single VM

Question

Greetings,
I have a Server 2008 R2 SP1 Standard Hyper-V box running about 8 virtual machines on it.  The machine is  joined to a 2008 domain. 
Recently, I moved the .VHD file for a single machine from one folder to another folder.  After doing so, when I connect to ONLY that specific machine via Hyper-V manager, I receive the error: "Your credentials did not work.  Your system administrator
does not allow the use of default credentials to log on to the remote computer XXXXXX because its identity is not fully verified.  Please enter new credentials."
I have the "Use default credentials automatically (no prompt)" option checked in the Hyper-V settings, and I have tried checking and unchecking this box and saving multiple times.  I have also deleted the saved credentials and the system reports no
saved credentials.
I have attempted to change settings in the group policy (gpedit.msc) regarding enabling the Local Computer Policy > Computer Configuration > Administrative Templates > System > Credentials Delegation > Allow Delegating Saved Credentials with
NTLM-only Server Authenticaton setting, something I found in older blog posts here in the Hyper-V forum and on other websites, and it has not made any difference.
At this point, I can only assume this must be some sort of bug because I cannot identify any other possible solution for getting rid of this annoying Windows Security pop-up box.  There are no entries in the Windows event log that indicate anything
odd.  When I enter the correct username/password, I can still access the VM, but the credentials are never remembered, and ONLY for this single VM.
Does anybody have any knowledge of how to fix this issue?  I can't believe that just moving a VHD caused all these problems.
Thanks!

Answer 1

Ah, finally found a solution!  I cannot explain why this suddenly got changed other than to assume it must have had something to do with a recent Windows Update or me trying to install Remote Desktop Services and Network Policy and Access Services.
I roughly followed the directions from
KB954357 or this
older post on the Hyper-V forum.
FIX:
1) Run gpedit.msc on the Hyper-V host that exhibits the problem.
2) Enable the policy setting Local Computer Policy > Computer Configuration > Administrative Templates > System > Credentials Delegation > Allow Delegating Default Credentials with NTLM-only Server Authentication.  Click the Show... button
next to "Add Servers to the list", and add the value "Microsoft Virtual Console Service/*" without the double quotes.  Click OK.  Click OK again to exit the dialog box.
3) Run a command prompt and execute gpupdate /force to refresh the group policy.
4) Now try to log into a machine in Hyper-V manager with default credentials enabled, and note that you are not prompted.
Again, I don't know why I had to do this, but it's working fine now.