Q:

ubuntu switched back to ubuntu-2d in 12.04

This problem may have been reported earlier but I was unable to find a solution to this.
after trying to install Nvidia drivers my Ubuntu session changed to ubuntu-2d and I am unable to restore it to Ubuntu 3d. Which drivers I may need to install/remove to solve this problem?
For further reference, heres a pic of how my workspace switcher looks like when changing workspaces.

I would like it to be as it was when Ubuntu  was first installed.

A:

Found the answer to this question in another question of mine.
For further reference :
How can I uninstall a nvidia driver completely ?

