Ubuntu 14.04 Black Screen

If you get a black screen after rebooting in to a freshly installed Ubuntu 14.04, it is a problem with compatibility of video drivers and modes. To permanantly fix this,

Get to the grub menu at boot time by pressing right shift.

Select the first option and press e to edit.

At the end of the line starting with linux add nomodeset and boot.

Then open the /etc/default/grub file and add this line.

GRUB_CMDLINE_LINUX_DEFAULT="nomodeset vga=791"

close the file and run following commands.

grub-mkconfig

update-grub