Laptop came with windows 8 - touchscreen worked fine. Upgraded to win 10 - touchscreen not working, no drivers available etc. ASUS tech help useless, suggested screen broken! Any similar out there?

Did you get the drivers from Asus ? You may need to go onto their site to get the ones for the touchscreen.

You can try these methods.

http://answers.microsoft.com/en-us/windows/forum/windows_8-tms/how-do-i-turn-my-touchscreen-back-for-my-asus/7d9f05e9-1b27-43bf-9cdf-cac7aa5e06bd

Let us know if it helps.