Microsoft does the OS, the makers add drivers. The OS upgrade may or may not keep everything working. A lot of folk didn't know there are things the OS doesn't supply.
My Lenovo Flex 15 has lost its touchscreen capability after the Windows 10 upgrade. I have tried the common solutions like deleting the drivers, doing a driver roll-back and running the Windows hardware troubleshooter, all to no avail. Before I restore to Windows 8.1 does anybody have another solution?