The first thing you need to do if your touchscreen is not working is to determine if it is a power issue or a hardware issue. First, check the small remote control, which is wired and should be attached to the lower section underneath the touch screen next to the power cord. If you see a small green light shining on the remote control, that means there is power.
If there is power, depress the power button on the remote control to try to restart the computer. If the touchscreen still does not work, email Pynwheel Support to report the hardware issue, detailing the steps you have taken.