Here is what I did to get the touch-pad to start working again. My laptop is Gateway and a couple years old, running Windows 7
1. Start –> Control Panel
2. Double-click on Mouse icon (or button, depending on how you’re systems set up).
3. When a the Mouse Properties window pops up, choose the Device Settings tab.
4. Click on the Settings… button.
5. A new window pops up and on the right side there is a list of options – choose Tapping.
6. Once clicked, there is a check box that allows you to Enable Tapping.
7. Click OK to close out your windows and the tapping option should be enabled on your touchpad.