One of the ways to solve this is by first checking to see if your keyboard has a key that turns the touchpad off. If it doesn't – or the right setting is toggled – then head to Devices > Mouse & Touchpad > Additional mouse options.

A new window will appear. From here, select the tab that says Device Settings, then Devices, and then make sure the touchpad is enabled.

If none of these options work, press Windows Key + X, select Device Manager, then the option for Mice and other pointing devices, and update the driver. This should fix things.