Go to the Control Panel --> Pen and input devices. Look at the tab for touch. Ensure that the use finger for touch device box has a check mark in it.
There may also be a HP TouchScreen Configuration option in the control panel which will offer the option to enable or disable the touchscreen.
or
Use your touchpad and go to the upper right hand side to access the search charm and click on it. Type in Control panel and then hit the enter key.
Troubleshooting Touch Screen Issues