Hi Helen,
This issue may occur if touchpad drivers are not updated or corrupted.
I would suggest you to install latest touchpad drivers from the computer manufacturer website and check if it helps. If Windows 8 drivers are not available, I would suggest you to install the driver in compatibility mode.
http://www.samsung.com/in/support/download/supportDownloadMain.do
To install the touchpad driver in compatibility mode, I would suggest you to follow these steps.
a. Download the latest touchpad driver driver for Windows 7 from the manufacturer’s website and save it on your local disk.
b. Right click on the setup file of the driver and select “Properties”.
c. Select “Compatibility” Tab.
d. Place a check mark next to “Run this program in Compatibility mode” and select Windows 7 from the drop down list.
e. Let the driver install and then check the functionality.
Hope this information helps. Reply to the post with updated status of the issue to assist you further.