I have an XPS13 9350 which I purchased in July 2014. It's an i7 processor and was bought with touchscreen.
For some months I had not used the touch screen until a few weeks ago. However, when I tried to use the touch screen I found it no longer worked. On investigation I found that Dell diagnostics didn't even recognise that I had a touch screen.
I have done extensive research online but have found no solution. I have tried the HID power management process to no avail. In control panel I have no Pen and Touch icons so I assume Windows cannot see the touch screen either.
I have read that this issue is related to Windows 10 so it shows that it must be over a year since I last tried to use the touch screen. Obviously I don't use it a lot but it is annoying that the laptop is not working as specified.