I had this issue of my touchpad not working (no cursor or ability to click anything). The keyboard shortcut didn't work and I tried updating the driver but it didn't work either. What did work: I opened "Device Manager". I went to view and hit "Show hidden devices". The grayed out devices are the ones not functioning. Under human interface devices a few weren't working. The driver for "Input configuration device" was the root problem. I held it and hit the option to uninstall it and restarted my computer. The computer automatically re-installed the driver and everything works!