VirtualBox as a service on windows
http://vboxvmservice.sourceforge.net/
DON’T run the service using the Administrator account!
Steps required to run it as a “regular” user:
Start “secpol.msc” as Administrator
Select the “Local Policies” folder
Select the “User Rights Assignment” folder
Double click “Log on as a service”
Use “Add User or Group…” to add your non privileged user