Follow the below steps to disable the touchpad on your computer.
Click "Start" and then "Control Panel." Double-click the "Mouse" settings. Click the "Device Settings" tab, and click "Disable" to disable the touchpad. You can select "Enable" to use it again.
Or you can follow the below steps.
Step 1: Navigate to Settings > Devices > Touchpad.
Step 2: Turn off the Touchpad option to disable the touchpad and its settings.