When I copied the file VBoxDD.dll and Run VirtualMachine (error: The specified I/O port range intruded on an existing range. There is a I/O port conflict between two device, or a device tried to register the same range twice.)
I also saw that there might be internal problems in newer version WinDBG even without using VirtualKD.
Somebody said that with using newer version WinDBG, they couldn’t watch register window.