Is the touchscreen option enabled (it should be by default)
Go to Control Panel > Hardware and Sound > Pen and Touch,
Is the box that says "Use your finger as an input device." checked/have a tick in it.
Have you checked the Device Manager for any yellow ! or red Xs and in particular the HID entries, has the screen been disabled/removed from there.
Run the HP Scan now tool to see if any updates are suggested, details here
As the touchscreen is normally enabled by default so it may not be a Windows issue and especially as you have done both a system refresh and system restore but without success, there are some Microsoft suggestions here that you can try though.