Follow these steps to install the Guest Additions on your Debian virtual machine: Login as root; Update your APT database with apt-get update ; Install the latest security updates with apt-get upgrade ; Install required packages with apt-get install build-essential module-assistant ; Configure your system for building kernel modules by running m-a prepare ; Click on Install Guest Additions… from the Devices menu, then run mount /media/cdrom . Run sh /media/cdrom/ VBoxLinuxAdditions.run , and follow the instructions on screen.
(sober==TRUE) ? beer++:beer++; @komtec1