Change the Windows Update Services setting from Manual back to Automatic (Delayed Start).
(Doing so will block your system from automatically reinstalling or showing updates for version 19 of the driver.)
Run the Windows 10 "Show or Hide Updates" Troubleshooter Package and hide updates to the Synaptics TouchPad Driver.
Install version 18 of the Synaptics TouchPad Driver and Software.
Scroll down to HP Control Zone (published by Synaptics Incorporated) and uninstall it.
In the Control Panel, select Programs and Features.
Uninstall version 19 of the Synaptics TouchPad Software (HP Control Zone).
Check the box to delete the driver software for this device, then click OK to uninstall.
Navigate to the Driver tab and click Uninstall.
Double-click on the Synaptics SMBus TouchPad to bring up its properties.
Click the "+" next to "Mice and Other Pointing Devices" to expand that category.
In the Control Panel, select Device Manager.
Uninstall version 19 of the Synaptics TouchPad Driver.
Change the Startup Type to Manual and click OK.
Click Stop to stop the service from running.
Scroll down to Windows Update and double-click it to bring up its properties.
In the Control Panel, select Administrative Tools and open Services.
Change the Windows Update Services setting from Automatic (Delayed Start) to Manual.
Download the Windows 10 "Show or Hide Updates" Troubleshooter Package ( ).
If a Synaptics driver with a version number starting in 18 is NOT listed, download the driver directly from HP ( ).
If a Synaptics driver with a version number starting in 18 is listed, download it. Look for the download in the "Driver-Keyboard, Mouse and Input Devices" category. Filter by version, selecting Microsoft Windows 8.1 on the dropdown menu.
Navigate HP's Software and Driver Downloads site ( ) to find the latest approved driver for your model.
Download version 18 of the Synaptics TouchPad Driver and Software.