I have hp pavilion ts 15 notebook pc , also have the problem, touchscreen will work on startup for a few minutes, then decides to go out, have been trying to resolve problem for months. Windows 8.1 no drivers avail says I have latest drivers which are dated
6/2006. this is the latest post I found that is the MOST helpful, bust still does NOT fix them problem entirely(still have to do a lot of rebooting)
http://answers.microsoft.com/en-us/windows/forum/windows8_1-hardware/touchscreen-stops-responding-since-windows-81/5abf45a9-f87c-4a54-b9b3-aaaef918b1e9
everywhere I go on the web, has no answer, blames HP, HP blames Microsoft it is just a big mess for all of us. I have pretty much disables windows update except for important updates, I have pretty much figured out the problem lies somewhere there, before
or after preparing/getting windows8.1. that is where the problem happens. I just haven't been able to pinpoint which update it is (after dumping my computer 3 times in one 36 hr period) but this link above is the best help for me, so far, I hope it helps
others...I JUST RECEIVED MY COMPUTER IN DEC2013 RUNNING WIN 8 HP PAV TS 15 NOTEBOOK PC and upgraded to win 8.1 so if you have different circumstances, PROCEED AT OWN RISK but good luck!