There are many similar post on ask ubuntu and I have gone through them with little success.

I upgraded from 13.04 to 13.10 to 14.04 back to back. The upgrade from 13.03 to 13.10 worked fine. After the upgrade from 13.10 to 14.04 I ran into a problem. After logging into my computer I am left with only the background image and no other desktop or unity elements. No key bindings work ( ctrl+alt+t for example). I am able to drop into a terminal using ctrl+alt+(f1+f6). Once logged into a terminal I am able to run things like apt-get and other shell utilities. I can not run anything graphical without first telling the terminal where to send it by exporting display 0 export DISPLAY=:0 Once I have done that I can run gui based programs like Firefox.

One thing to note, if I run nautilus from the terminal it shows me the desktop and the bar at the top of the screen with the nautilus options ( File Edit View Go Bookmarks Help ). I have tried re-enabling unity from CCSM, no change, I have reinstalled unity and Ubuntu-Desktop, no change. I have uninstalled and reinstalled nvida-current drivers , again, no change.

I have done everything I can think of to investigate this problem ( which is not much since I am still pretty new to this). If there is anything I should do to further investigate this let me know and I will run it asap. I am still able to switch the standard output to a file on the desktop and access it from there. Any help would be greatly appreciated

• edits to grammar and spelling were applied.

Update:

Based on the suggestions made in this post. I did the following;

 sudo apt-get install --reinstall ubuntu-desktop

 sudo apt-get install unity

 sudo apt-get purge nvidia* bumblebee*

 sudo apt-get install nvidia-prime

 sudo shutdown -r now

Now, after I log into my computer I see the items on my desktop. I can also open nautilus by pressing ctrl+n. The ability to right click has returned which allows me to open a terminal. However, ctrl+alt+t still does not work. I am unable to grab and move any windows around or bring program windows from the back of the desktop to the front by clicking on them. They stay stacked in the order I opened them, with the most recent window on top. I checked Compiz Setting Manager again and unity is activated.

Update 2:

I think this may be an opengl problem. I ran the following command in the Termial;

DISPLAY=:0 unity

and I get the following output before the terminal hangs.

 compiz (core) - Info: Loading plugin: core

 compiz (core) - Info: Starting plugin: core

 unity-panel-service start/running, process 2707

 compiz (core) - Info: Loading plugin: ccp

 compiz (core) - Info: Starting plugin: ccp

 compizconfig - Info: Backend     : gsettings

 compizconfig - Info: Integration : true

 compizconfig - Info: Profile     : unity

 compiz (core) - Info: Loading plugin: composite

 compiz (core) - Info: Starting plugin: composite

 compiz (core) - Info: Loading plugin: move

 compiz (core) - Info: Starting plugin: move

 compiz (core) - Info: Loading plugin: place

 compiz (core) - Info: Starting plugin: place

 compiz (core) - Info: Loading plugin: snap

 compiz (core) - Info: Starting plugin: snap

 compiz (core) - Info: Loading plugin: commands

 compiz (core) - Info: Starting plugin: commands

 compiz (core) - Info: Loading plugin: compiztoolbox

 compiz (core) - Info: Starting plugin: compiztoolbox

 compiz (core) - Error: Plugin 'opengl' not loaded







compiz (core) - Info: Loading plugin: resize

 compiz (core) - Info: Starting plugin: resize

 compiz (core) - Info: Loading plugin: regex

 compiz (core) - Info: Starting plugin: regex

 compiz (core) - Info: Loading plugin: mousepoll

 compiz (core) - Info: Starting plugin: mousepoll

 compiz (core) - Info: Loading plugin: imgpng

 compiz (core) - Info: Starting plugin: imgpng

 compiz (core) - Info: Loading plugin: vpswitch

 compiz (core) - Info: Starting plugin: vpswitch

 compiz (core) - Info: Loading plugin: session

 compiz (core) - Info: Starting plugin: session

 compiz (core) - Info: Loading plugin: workarounds

 compiz (core) - Info: Starting plugin: workarounds

 compiz (core) - Error: Plugin 'opengl' not loaded

I am not sure what to do about this, opengl does not seem to be missing in general since i am able to run graphically intensive programs. However, I am not sure if the opengl plugin is a different thing then opengl used for things like gaming ( I feel shame admitting that ). I am off to do research on this and will report back when I have some more information.