Either of the following two methods will install and configure the VirtualBox Guest Additions on Debian Wheezy (7.0 or 7.1) – assuming you have clicked on “Install Guest Additions” option on the VM Menu. # apt-get update # apt-get install build-essential module-assistant # m-a prepare # mount /media/cdrom # bash /media/cdrom/VBoxLinuxAdditions.run or # apt-get update # apt-get install gcc make # apt-get install linux-headers-$(uname -r) # mount /media/cdrom # bash /media/cdrom/VBoxLinuxAdditions.run Contrary to what some people have experienced, I had no trouble invoking the GNOME 3 Shell in Debian 7.0 or 7.1 when running in VirtualBox 4.2.16 under Microsoft Windows