Unity Launcher and Menu Bar Missing

While it appears to be an issue that has plagued a hand-full of Ubuntu users, for at least 6 years, it still seems difficult to find a fix.
On installing Nvidia drivers in Ubuntu, after logging in, the entire Unity and menu bar are nowhere to be seen.

Rather than being presented with the usual desktop interface.

The user has displayed for them the lovely purple Ubuntu background instead (in whatever incarnation that version is using).

Luckily there's a fix...

...or a few fixes, as presented on the askubuntu forums:

askubuntu.com/questions/17381/unity-doesnt-load-no-launcher-no-dash-appears

But before you start getting frustrated trying out every single fix listed, try this one:
(in terminal)

export DISPLAY=:0
sudo dconf reset -f /org/compiz/
setsid unity 

If that one doesn't work for you then head over to those forums.