Before installing new drivers, remove the old ones to prevent conflicts.
Windows Update rarely provides the touchscreen firmware or the DCHU (Digital Compass Hub Unit) drivers. You will still need manual downloads for full functionality. acer iconia w4-820 drivers
If any issue persists, uninstall the device and driver, then reboot to let Windows reinstall from the driver folder you downloaded. Before installing new drivers, remove the old ones
Even with the correct Acer Iconia W4-820 drivers, problems can arise. Here are solutions to the most frequent complaints. Before installing new drivers