Make sure that you can ping the VM from the host. I had to setup the host-to-VM networking stuff so that the VM could communicate with the host. Make sure firewalls are off or have the right ports open, in the VM the make sure the visuallDDK app is running as admin.
This problem is not related to network communication (pinging & etc).
Did you install the VBoxDD.DLL file from VisualDDK according to installation instructions (http://virtualkd.sysprogs.org/#installation)?
I’ve rename vboxdd.dll to vboxdd0.dll in virtual box directory and I’ve copied the vboxdd.dll from visualddk to virtualbox directory, but still problem…
Please try debugging using WinDbg+VirtualKD (start VMMON.EXE or VMMON64.EXE, select your VM, select the correct OS instance, press “Run Debugger” from VMMON).
If the WinDbg debugging fails as well, double-check your VM settings and VirtualKD installation.
If WinDbg debugging works, but VisualDDK still fails, ensure that the correct VM name is specified and that you are not running WinDbg while connecting from VisualDDK.
Anyway, feel free to post here after you try WinDbg.