Half of my laptop keyboard doesn't work, and I was wondering if I could turn off the laptop keyboard, so that I can sit an external keyboard on top of it. I have an Acer Aspire, and the only thing I can do is shut off both keyboards.
In Windows Device Manager you should be able to disable/uninstall the keyboard. I believe windows may try to reinstall on each reboot, but the uninstall could possibly be scripted. Though mythealias is also crrect above, you should be able to disconnect the cable, your manufacturer should provide a disasembly/repair guide; if you are comfortable with that you may be able to get a new keypad off ebay and install, which is probably more ergonomic that sticking a regular keyboard right ontop.