The touchpad features in the Control Panel cannot be accessed or changed after adding an external IBM® PS/2® compatible mouse, a serial mouse, or a USB mouse.
The touchpad features in the Control Panel may not be changed or accessed after adding an external IBM PS/2 compatible mouse, a serial mouse, or a USB mouse if the software for the external mouse has overwritten the touchpad drivers. This may disable some of the touchpad features, for example tapping.
To resolve this issue, reinstall the original touchpad drivers.
NOTE: It may be necessary to uninstall the software added for the external mouse.