The trackpad on your laptop is great when your working without a mouse, but not so much when you're using the keyboard and a mouse, or just want to type a long document or email. Constantly brushing the trackpad sends your cursor from one side of the page to other and gets annoying.
So how do you quickly turn the trackpad off?
Here are a couple of ways -
Toggling using FN + F key
Most commonly, if you look at your F keys, you'll find one with the following icon (or something similar). It may not be on the F9 button, but one of them should have it -
Your laptop will also have a FN (or similar) button -
If you hold the FN button and press the F key with the mouse icon, depending on what laptop you are using it will either toggle the trackpad on or off or display a settings dialog to enable you to select to do so.
Toggling using direct toggle button
Some laptops have a button above or near the trackpad to turn it on or off -
and if I press it, the light turns off, indicating the trackpad is off -
Some laptops may not have an indicator light, but may display a message on your screen instead.
NOTE: Some Dell Laptops are known to re-activate trackpads automatically after a certain amount of time. This is deliberate and cannot be overridden.
Automatically disabling the trackpad if an external (USB) mouse is connected.
If you want to auttomatically disable your trackpad whenever a USB mouse is connected to your laptop, you can do the following -
Go Control Panel > Mouse
Under Device Settings, Click the box that says "Disable internal pointing device when external USB pointing device is attached"