I successfully upgraded yesterday from 8.1 and this morning I was looking at the new 'desktop switcher.' I was looking for an OSX style touchpad gesture to switch between them. I followed the instructions on the second part of to try and get a custom synaptics driver working. In the course of this, I uninstalled the factory synaptics drivers using 'Programs and Features' in the control panel. When trying to install the new custom drivers, I got the error: 'A newer version of the Synaptics Pointing Device Driver is installed. If you want to install the older version of the Driver, please uninstall the current Synaptics driver by selecting 'Synaptics Pointing device' from the 'Add/Remove Programs' Control Panel, then run Setup again.' At this point, my touchpad no longer works at all.
So I tried to restore the driver to what it was originally. My first thought was to get windows update to update it for me. I got 'Lenovo synaptics touchpad driver' to appear in the list of updates. When trying to update, it threw the error: 'Synaptics driver update for Lenovo Pointing Device - Error 0x80070002' After rebooting and attempting again with no success, I turned to Lenovo's website. I found the support page for my device: Seeing no Windows 10 driver, I tried to download the 8.1 driver. Hp 4540s Windows 10 Drivers. It appears to run, even copying files into Program Files, but when I hit 'Finish' in the msi style installer, a windows 10 notification appears saying 'This app can't run on this PC Realtek bluetooth suite doesn't work on this version of windows' that links to this page: when clicked.