Congratulations to your anniversary
run this, to make sure all packages are installed:
add your user to the vboxusers group. This is a permission thing. so you are allowed to use virtualbox
sudo apt-get install virtualbox-ose virtualbox-ose-modules-`uname -r`
re-login. this will close all apps and restart the x-server, so make sure all work is saved.
sudo adduser $USER vboxusers
here comes the thing you actually asked about:
open a terminal and run:
so you only missed the sudo (super user do) thing. This is essential, because normal users dont have the permission to start/stop services.
sudo /etc/init.d/vboxdrv restart
now you should be able to run virtualbox