Disk drive boot problem: The disk drive for /tmp is not ready yet or is not present!
Solution 1:
Try this. Just press Ctrl + Alt + T on your keyboard to open Terminal. When it opens, run the command(s) below:
sudo mv /tmp /tmp_old
sudo mkdir /tmp
sudo chmod 1777 /tmp
Reboot, and it should be OK.
Solution 2:
This is a bug in Ubuntu - Ubuntu bug #1091792. It was fixed in mountall-2.48 for Ubuntu 13.04. Unfortunately the latest version in Ubuntu 12.04 is mountall-2.36.4, so it is not fixed (and, presumably, never will be).