I have a DELL Laptop Latitude D630 and Ubuntu as OS. Touchpad has always worked perfectly for more than a year now, first with Ubuntu 12 and now with Ubuntu 14.04 after the upgrade. Today the touchpad stopped working suddenly after logging in. It is not responding at all. The wireless mouse is working fine. I also noticed a weird notification popping up at some stage saying wireless keyboard battery was low or something like that. However I am not using a wireless keyboard as it is a laptop and I am not using the battery as it is plugged in. Any clue how I can restore my touchpad functionalities?