I bought my laptop 'Lenovo Flex 15' about a two weeks back. The touch screen was all working fine until yesterday!! It suddenly stopped functioning! I read all possible articles relating to this and tried to fix it but none of it works. Some quote it to be a bug relating to the power management in windows 8. Even this did not help me out.

I tried the following:

1. Tried reinstalling windows 8 with a complete cleanup, basically a reset (did not want to try upgrading to windows 8.1 since all those users face the same problem)

2. Device Manager > Human interface devices > USB Input device. In this I disabled the option 'Allow the computer to turn off this device to save power' in the power management tab. Also disabled 'Selective USB suspend' in power settings.

I understand that there are a lot of users out there facing similar issue with their touch screen laptops running windows 8. We bought a touch screen laptop only looking at the functionality of windows 8 and here it is not letting use the touch screen :/ Requesting Microsoft to find a quick fix for this at the earliest

This issue occurs when there is no updated drivers are there for hardware. As you have tried most the troubleshooting including reset, I would suggest you to try installing the updated drivers for Touchscreen and chipset drivers and check if it helps.

Here is the link to updates the drivers from Lenovo website.
http://support.lenovo.com/en_JP/downloads/detail.page?DocID=DS037056

If updating the drivers did not help, then it would be better to contact the computer manufacturer for further assistance as this is a 2 weeks old computer.

Lenovo Support: http://support.lenovo.com/en_US/