HyperV Error: A Virtual Disk Provider for the specified file was not found

I recently blew an hour trying to attach a VHD inot a HyperV on a new Server 2008 R2 64Bit Standard server but received “A Virtual Disk Provider for the specified file was not found” which was not cool.

The solution was a small registry change as documented http://support.microsoft.com/kb/2013544 

1)    Start Registry Editor.
2)    Visit the following registry key: “HKLM\SYSTEM\CurrentControlSet\Services\FsDepends”
3)    Under the “FsDepends” key, change REG_DWORD value “Start” from “3” to “0”
4)    Restart the computer