Quite often, I'll reboot my machine, i.e., after an update or for some other reason. When the machine reboots, elementary OS won't boot with a desktop, but rather just a command prompt. I can log in via the shell and that sort of thing, but there's no desktop environment.
I am using 64bit Luna 0.2.1
Any idea how I can 1) avoid this from happening; or 2) if it does happen, how do I launch the desktop environment from the shell?