Answer:
for some laptop's there is a very tiny button above the touch pad but below the keyboard just click on it
for other laptop's:
Step 1 - Click the start button.
Step 2 - On the start menu, click on the control panel.
Step 3 - On the control panel menu, click on the hardware and sound icon.
Step 4 - Under devices and computer icon, click on mouse.
Step 5 - The mouse properties menu opens: For laptops with the synaptic touchpad, the touchpad can be disabled in the synaptic tab on the mouse properties menu. To put short, if you find any tab labeled ''synaptic'', click on it to disable the touchpad immediately. Continue to the next step if you can't find any such tab.
Step 6 - Click on the hardware tab. You should now be faced with two icons depicting a mouse. Highlight the PS/2 Compatible mouse and click on the properties button.
Step 7 - On the ps/2 compatible mouse properties menu, click on "change settings".
Step 8 - Click on the driver tab.
Step 9 - Click disable.
Step 10 - Confirm your action and click OK.
You may need to restart your computer at this point. After you restart, the laptop touchpad should be disabled. To re-enable the touchpad, you simply need to do the opposite of what you just did to disable it.