Hello Cindy ,
First of all Restart your computer after restarting the computer it will not gonna be work then do these steps
1- Enable your touchpad:-
If your laptop has a function key that enables/disables the touchpad. by pressing it Fn key + F5, Fn + F6 .
2- Touchpad devices enable or disable-
:-Click on start
:-Click on settings
:-Go to the devices
:-Click on mouse and touchpad
:-scroll down
:-Click on additional mouse go to mouse properties.
:-Click on devices.
:-See there if touch pad is disabled then select it on enable mode.restart the computer
If it does not work then visit this articale [https://goo.gl/D1Gpbz|fix the touchpad related problem step by step]
3-Update your drivers-
.Press windows key + R key together.
.Type in the run dialog box- devmgmt.msc.
.Enter and go to Mice and other pointing devices.
.Find your touchpad driver and Right-click on your touchpad driver and Click Update Driver Software.
if nothing works than -
.Go to device manager again.
.Un-install your touch pad driver – By right click on your touchpad's driver or press windows key + R key.
.Type appwiz.cpl in run box.
.Un-install your driver.
.Download your touchpad driver by your laptop brand name and model no. through manufacturer site.