Problem

i8042: No controller found

Article is specific to NVIDIA drivers

What it means

Means there is no PS/2 ports. Has no affect on system performance, but that message shows a few seconds before reaching GUI.

Reach terminal, and attempt Method 1 or 2 to get the GUI up and running again.

Ctrl+alt+F2 (or F3/F4)

Ctrl+(left/right)Arrow key

Reach terminal

rm -rf /etc/X11/xorg.conf

nvidia-xconfig

reboot

From existing .run file that is initially included with your system

2 possible destinations:

/usr/local/CUDA_Install_Files/NVIDIA-Linux-x86_64-384.xx.run

or

search your /root directory

Be sure to 'init 3' before attempting to re-install the NVIDIA driver