Unable to remote control Hyper-V VM after installing SharePoint 2010 on Windows 7

True to form, you only discover something isn’t working when you’re in a desperate hurry. We use lots of Hyper-V VMs here at Black Marble and they are mostly running on our four node cluster. I use Failover Cluster Manager and this morning I couldn’t connect remotely to any of the Hyper-V VMs. I kept getting an error:

Virtual Machine Connection:
A connection will not be made because credentials may not be sent to the remote computer. For assistance, contact your system administrator.
Would you like to try connecting again?

A quick search suggested that the credssp settings on the host servers were broken. A quick test showed that they weren’t – the problem was local to my machine.

The only thing I had changed recently (try yesterday!) was to install SharePoint 2010 on my workstation. OK, I’ll be fair – that means a whole load of pre-requisites, so it’s not that simple!

I decided to check my machine and look at the settings which had been suggested as being wrong on the hyper-v servers. Sure enough, my workstation now had the credssp elements and sure enough, they didn’t match the example I’d found.

So if you get the same problem, copy the text below into a .reg file and import it into your registry. It should fix the problem.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults]
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowDefaultCredentials]
"Hyper-V"="Microsoft Virtual Console Service/*"
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowDefaultCredentialsDomain]
"Hyper-V"="Microsoft Virtual Console Service/*"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowFreshCredentials]
"Hyper-V"="Microsoft Virtual Console Service/*"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowFreshCredentialsDomain]
"Hyper-V"="Microsoft Virtual Console Service/*"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowFreshCredentialsWhenNTLMOnly]
"Hyper-V"="Microsoft Virtual Console Service/*"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowFreshCredentialsWhenNTLMOnlyDomain]
"Hyper-V"="Microsoft Virtual Console Service/*"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowSavedCredentials]
"Hyper-V"="Microsoft Virtual Console Service/*"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowSavedCredentialsDomain]
"Hyper-V"="Microsoft Virtual Console Service/*"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\Credssp\PolicyDefaults\AllowSavedCredentialsWhenNTLMOnly]
"Hyper-V"="Microsoft Virtual Console Service/*"