Yesterday I finally purchased the Dell XPS 2720, a deal of a lifetime investment for me.
An hour after the easy set up and commissioning wherein the touch screen had been working ultimately properly, the screen was no longer responding to touch.
As far as I remember, and inasmuch as related, the last response to the touch had occurred before adding the Arabic language to the keyboard and/or trying the Chassis-Based Switches.
I have been searching for this error and the only responses that address this particular issue are here on the Dell forums not anywhere else on the web. I applied all the solutions suggested including installation of the BIOS file via the Dell's support "get drivers and downloads" section using the Service Tag, Calibration which I was not able to locate on my machine as if the touch screen is not there at all, and the four steps suggested by Dell support in one of the answers. However, non of the solutions were applicable to the machine.
In the United Arab Emirates, Dell's phone support was not able addressed my problem with no assistance as my warranty does not cover phone assistance during weekends.
In the meanwhile, during the first commissioning of the lifetime investment computer, you can imagine how much a 10-year-Dell customer would feel with such disappointing issue.
Any help from the members here or any other support is highly greatly appreciated.