I've added to Startup Applications this command:
notify-send "Hello User" "Welcome back to Ubuntu 12.10" --icon=/usr/share/unity-greeter/cof.png -a "Computer" -u critical
It does not appear at startup or login but works when run from terminal.
I've also tried putting the command in
/etc/rc.local, but it doesn't work.
How can I run this command at each startup/login?