How do I turn off the touchpad?

When I type on my laptop, my palms are generally resting on the touchpad and quite often, I end up moving the pointer and end up setting the cursor in a different location. If I'm not touch typing at the time, I won't notice for about a paragraph or so. I can get around this by elevating my hands somewhat when I type, but that starts to cramp my hands and wrists. I looked in the documentation that came with the computer and in the control panel options, but couldn't seem to find a way to do it. Could someone tell me how plz? I'm running Vista Home Premium on a Dell Inspiron 1721, if that helps.

Typically, you can change these device settings easily by opening the
"Mouse" icon in your windows "Control Panel" folder.
at the very end tab you have something called "Dual Pointing Device".

You can enable/disable from there

Download the Synaptics drivers for the pointing devices in your laptop, these allow you to set advanced properties for the touchpad such as sensitivity for accidental brushing the palm on the pad, or even turn it off.

As far as I know, Dell continues to use Synaptics touchpads and pointing sticks in its laptops. The drivers provided on Dell's site are modified older versions of Synaptics' own drivers, which lack some of the advanced options.

My Dell D620's use the Alps Touchpad.

Synaptics drivers might work there as well. Unfortunately, Alps does custom built drivers for individual manufacturers, so all you're getting there is what's on Dell's support site.

Thanks for the replies :) .

There are many versions of touch pad drivers that work in place of the Alps version from Dell. This includes Alps drivers from other manufacturer's websites and Synaptic drivers as well.

I've had no issues using the Alps drivers and have not encountered any features in the Synaptic drivers that are not also present in the Alps drivers.