After upgrading from 11.10 to 12.04, virtual box stopped working.

I've run the following to try to fix it:

sudo aptitude update

sudo aptitude install dkms

sudo /etc/init.d/vboxdrv setup

but when i run the last command I get:

bash: /etc/init.d/vboxdrv: No such file or directory

When I try

sudo /etc/init.d/virtualbox start

I get:

 * Starting VirtualBox kernel modules

 * No suitable module for running kernel found

I've also tried:

sudo dkms install virtualbox/4.1.2

and got:

Error! Could not find module source directory.

Directory: /usr/src/virtualbox-4.1.2 does not exist.

I've also tried installing linux headers:

sudo apt-get install linux-headers-$(uname -r)

but they were already installed.

From what I've read re-installing may not fix the problem. Is there a way I can fix virtual box?