|What is the make of ur computer ? |
Some of the Laptops are coming with a feature where they can be disabled ,
A orange light aboutve the touch pad will let you know the status of the touchpad if it is lite up orande then touch pad is disabled and to enable...
Start---->Control panel--->Mouse icon---->and then look for touchpad setting and look for the option disable touch pad when external mouse is plugged in , if this option is checked uncheck the option and then click on apply and then click ok that should fix the issue with touch pad or else go to device manager uninstall drivers for touch pad and reinstall...:)