I spent hours figuring this one out. In the BIOS you need to change the touchpad option from Advanced to Basic and it will start working again. Apparently a special driver (called 'I2C HID Driver') needs to be installed for it to work in advanced mode after the upgrade. I haven't figured out how to get the driver yet but eventually I will.
To get into BIOS, reboot and keep hitting F2 until the bios screen pops up. Installing the ELAN driver doesn;t make any difference if it can't see the touchpad in the first place.
Broadcom Wireless LAN Driver. Windows 10 64 bit (49.24 Mb). Wireless LAN Driver (WB335 HAI). Install Acer Aspire ES1-512 laptop drivers for Windows 10 x64, or download DriverPack Solution software for automatic drivers intallation and update. Just view this page, you can through the table list download Acer Aspire E 1-531 drivers for Windows 10, 8, 7, Vista and XP you want. Here you can update Acer drivers and other drivers. Driver DR is a professional Windows drivers download site, it supplies all devices for Acer and other.
I normally turn off the touchpad and use a mouse anyway but I don't always carry a mouse with me so it is inconvenient not to have the touchpad. Hope this helps. Hp Deskjet 2510 Drivers For Windows 10.