Hello. I do not know what type of computer you're using but i searched some various forums with the issue you are having and came to this conclusion.
an Averatec 6200 series that had this exact problem.
disconnect the usb mouse, printer, bluetooth, power pack, internet connection and then flip it over and unplug the battery, with no power pack and no battery then push and hold the power button in for about 20 secounds, Averatec calls this a "hardware reset" and it worked for them.
or in simpler terms this:
Hard power-off (hold the power button until the laptop turns off)
Unplug the AC adaptor
Remove the battery
Re-Plug in the AC adaptor
Hold ctrl and Esc. and then turn the power on.
You should arrive at a black (all black) screen.
Hard power-off again,
then turn the power on.
Then make sure your touch pad is "On" with the FN+F7 key combo.
Once it is working, go ahead and put the battery back in.
I would also be able to help more if you gave details on what type of computer it is make, graphics card, ect.. What you were doing before this occurred. Did you download anything new, change settings, ect.