Touch screen Problem

I've heard of people somehow accidentally disabling the touch screen bit. Sometimes this happens when people try to cleanup their startup programs and don't pay attention to what they're turning off. Sometimes driver updates, either from Windows Update or just updating drivers through the built in software can create issues with different hardware. Worst case scenario a cable could have been routed improperly when it was manufactured and it has gotten pinched, or if you're lucky, just got unhooked.
 
Might need to reinstall the monitor driver. Go to the manufacturer website and see if maybe they have some kind of driver detector tool or something. Most companies have them, you just download it and scan. If not, then punch in your service tag on their website and download and display screen drivers you can find that match your setup.