You may need the following iso file to install / activate more features within VirtualBox:
http://download.virtualbox.org/virtualbox/
Start / Stop & Restart your Virtual PC using VBoxManager from the terminal or within a script:
NB: The VPS name only needs to be in “” if it contains spaces!
To Start: vboxmanage startvm "Your VPS Name"
To Power Off:
vboxmanage controlvm “Your VPS Name” acpipowerbutton
To Reset:
vboxmanage controlvm “Your VPS Name” reset
To find the name(s) of your Virtual PC’s use:
vboxmanage list vms