I can't use tethering on my tablet

Your computer and your tablet haven't been set up for tethering correctly

Set up your tablet and computer for tethering.

1 of 7 steps Connect the data cable to the socket and to your computer's USB port.
2 of 7 steps Slide your finger down the display starting from the top edge of your tablet.
3 of 7 steps Press the settings icon.
4 of 7 steps Press Mobile hotspot and tethering.
5 of 7 steps Press USB tethering until the function is turned on.
6 of 7 steps An internet connection from your computer via your tablet is automatically established.When the connection is established, you can access the internet from your computer.