You can disable the touch pad in the [Touchpad] tab in [Sony Notebook Setup]. Please refer to the following procedure:
1) Click [Start] -> [VAIO] -> [Utilities] -> [Sony Notebook Setup].
2) Click the [Touchpad] tab and click the [Disable Touchpad] option button.
3) Click [OK] to close the [Sony Notebook Setup] window.
A part of the touch pad function may not be disabled when you disable it in [Device Manager].