I was trying to fix an issue with Ubuntu 14.04: my screen would freeze when the computer was woken after being asleep. I followed the instructions here (Ubuntu 14.04 System freezes on wakeup from suspended state) which lead me to the solution posted here (Ubuntu 14.04 install NVIDIA driver) to install an updated NVIDIA driver. I followed the steps there. This solved my problem, but a new one cropped up: a thick (1 inch) black border appeared around all of my windows, including popups. So, I decided I would get rid of NVIDIA--the old problem was less of an issue than the new one. I ran "sudo nvidia-uninstall" from the terminal, and then rebooted.
Upon reboot, I attempted to sign in, but when I did nothing happened: neither the launcher nor the dash appeared. This seemed to describe the trouble I was having: Unity doesn't load, no Launcher, no Dash appears. So, I followed the most popular solution here, installing Compiz Settings Manager. I followed the instructions on that page to turn on Unity. And then I returned to the terminal and rebooted, as instructed.
At this point I still cannot sign in. When I return to the Compiz Settings Manager, the Unity Plugin is listed as turned on.
From here, I tried resetting Unity by installing the Unity Tweak Tool, and followed the steps here: Ubuntu Desktop does not load. Everything installs fine. When I try to run the unity tweak tool, however, I get a repeating error message of "dconf-WARNING **: failed to commit changes to dconf: Cannot autolaunch D-Bus without X11 $DISPLAY". I then made sure that I had X11 installed, and followed the instructions here: How to install X11/xorg?. Still the problem persists.
Any help would be greatly appreciated. I have no idea what to do to fix this, and really need my computer to be working.