How To Disable Guest Account In Ubuntu 12.04

Here is how to disable disable guest account in Ubuntu 12.04:

1) edit fileĀ /etc/lightdm/lightdm.conf

sudo nano /etc/lightdm/lightdm.conf

2) add to it allow-guest=false so ti looks like similar this:

[SeatDefaults]
user-session=ubuntu
greeter-session=unity-greeter
allow-guest=false

3) restart lightdm service:

sudo restart lightdm
4) and... profit :)!