Touchpad stopped working once before after upgrade to Win 10. I upgraded BIOS and Synaptics driver, that fixed it.
Now it suddenly stopped again. Touching the pad to move pointer doesn't work, nor do gestures, but the corner left and right clicks (for select and context menus) work. External USB mouse works OK.
BIOS is still current. Upgraded Intel chipset. Uninstalled Synaptics and reinstalled driver. Win 10 is 1511 Build 10586.679.
Out of ideas now. Help plzzzzz. THx.