Try this 1
1) First make sure that the Touchpad is not locked. Hold the "Fn" key and then
press "F1" key.
[Note : A touchpad symbol should be there on the "F1" key or else look for the
symbol in the function keys and use that particular key with the combination Fn.]
2) Unplug the power cord --> Remove the battery --> Hold the power button for
60 seconds --> Connect the power supply then try to switch ON the laptop and
later put the battery back into the laptop.