The typical way to uninstall drivers for hardware (your touchpad is a hardware item...may be seen in Device Manager as mouse)...is via Device Manager.
Device Manager Basics - http://www.cybertechhelp.com/tutorial/arti...-manager-basics
Go Start/Run...type devmgmt.msc and hit Enter. That should get you into Device Manager which reflects hardware components of the system.
Scroll down to mouse, click the plus sign to the left, that shows the detail item.
Double-click the particular item and that should reveal a number of tabs. Select the tab marked Driver, click Uninstall button on that tab.
Reboot the system and see what happens.
Windows can install drivers automatically...if it already has them in storage. Installing XP includes a folder for various drivers and these can be used to install hardware.
The drivers cache in XP may not necessarily have all drivers, particularly (IMO) for newer systems...hence the need (for some) to install drivers from either a CD or downloaded drivers which have been saved on the hard drive.