Is the touchscreen of your HP Envy TouchSmart thinks like something is touching it and disrupting whatever you are doing? So do you want to disable the touchscreen while you are not using it? Then you can follow the steps below:
You can do this to going to Device Manager by pressing the Windows logo key + X and then selecting Device Manager from the list
> click the little arrow (>) next to Human Interface Devices to expand the list
> right click on HID-compliant touch screen
> choose disable.
This will have disabled the touch ability.