The easiest way to revert all the changes back to an earlier date and time is to do System Restore if your using Windows 7 or Vista but it's Windows 8 or 10 it's not applicable.
If your using Windows 8 or 10 here's what you can do.
- Go to Device Manager and look for Touchpad and expand it.
- Right click on the Touchpad driver and select Uninstall then reboot your laptop that should reinstall the driver automatically.
- After the reboot test if your touchpad is working as it should.
- If not go to Control Panel and look for Mouse
- In Mouse Properties you can change how it should behave (clicking, pointing and calibration.)