Having a similar problem with my XPS 12 (9Q33).

Everything was working fine. Just had my screen replaced today (also for image retention issues). Since the replacement my touch screen has not been working. My device manager also shows I2C HID Device not working "The device cannot start. (Code 10)"; "A request for the HID descriptor failed."

Tried updating/disabling/enabling/uninstalling through device manager with no luck.

I went to the Dell website and tried updating my display firmware to A01 but this failed with two error messages: "Aux channel error!" and "DPCD registers mapping error"

Really hoping someone has a fix to this.

Same problem here.  XPS12 9Q33.  Several times in the past year the touchscreen has not worked.  Other times Dell technical support was able to fix it while I was on the phone.  But this time they gave up. 

In the past it was always fixed by doing something in the software, but I do not recall what it was.  So now I am working without a touchscreen.

My problem was in fact related to improper hardware being swapped into my unit and Dell resolved the issues.

Ghriddle, your problem sounds like a different issue. The intermittent nature makes it sound like a driver issue.