Permanent disabling of touchpad

I own a Dell Inspiron N5050 Notebook running Windows 7 Home Premium. I am trying to permanently disable the touchpad. I installed the appropriate driver in order to manage my touchpad preferences, and successfully disabled it - but once the machine was rebooted, the touchpad was on again. I really don't care if I will need to keep disabling it each time I boot up, but does anyone know of a way to permanently disable it?

Approach 1: BIOS

The touchpad can usually be disabled in BIOS. On my Dell Latitude E6430s, the option is POST Behavior, Mouse/Touchpad. There is even an option to disable the touchpad only if an external mouse is attached.

Approach 2: Device Manager

Open Control Panel, System, Device Manager. Navigate to the mouse, right click on it and click Disable.

Approach 3: Physically unplug

According to a disassembly video, it appears that you can unplug the touchpad by removing the keyboard (at 3:45) and removing the small ribbon cable near the touchpad.

https://www.youtube.com/watch?v=NR0iRYLEO9s

(Win)+X opens the "Windows Mobility Center".  On my Dell Inspiron (running Windows 7), it looks like this:

I disabled my touchpad there, and it has stayed disabled through many reboots.