i encountered the issue described in this question :
and i used one of the solutions suggested there, re-installing and registering services...etc and it worked for me, i managed to run VirtualBox without errors, but once i try to run any given Virtual Machine, the Virtual Box hangs at the stage :
"Creating process for virtual machine" (GU/Qt)....(1/2)"
i tried all solutions i can think of, and things i found on the net but nothing really worked.
can you please provide some assistance, this is very critical.