Please run Keyboard troubleshooter on the system by typing Troubleshoot onto [Cortana] search box. The troubleshooter find and fix problems with your computer's keyboard settings.
If Troubleshooter doesn't fix keyboard:
Uninstall / reinstall keyboard driver in device manager.
1. Right click keyboard driver and select Uninstall
2. Select Action on the Device Manager menu bar
3. On the Action menu, select Scan for hardware changes to reinstall driver
If that doesn't work:
1. Right click keyboard driver
2. Select Properties
3. Select Roll back Driver under the Driver tab
Lastly, if keyboard still doesn't work normally:
Roll system back to the most recent successful configuration of the registry, restart the computer in Safe Mode and select the Last Known Good Configuration option. Hopefully this will finally fix the computer's keyboard.
Windows April Update probably didn't install properly. Try opening Settings, Update and Search for updates again. If the touchpad doesn't work, attach a usb mouse. Windows supplies the kb driver so don't uninstall the kb. It would be best to force a shutdown before updating windows by holding down the power button for 30 seconds or more until the lights go out. Wait a bit and try starting up again. Then do another update. It should pick up where it left off.
Check the icon tray for an icon labelled "FilterKeys".
If no icon is present try using Windows search to find it or press and hold shift eight times.
Hope this helps!
Try to install the "Intel Management Engine Components Installer" from Dell Drivers. It's under the "Chipset".
Hope your problem will be solve.