Strange things do happen every now and then on my laptop. I have done some upgrades on security patches and software and noticed that the Synaptics touchpad does not work properly. Usually, a tap on the touchpad is equivalent to a left click on the mouse and a double tap would be equivalent to a double click on a mouse.
The Synaptics touchpad in general works, but the tap-to-click functionality does not work as before. I need to use the touchpad left button to select via click or double click to select some items. There are some settings which might have been affected. I checked on Windows XP’s Start -> Control Panel -> Mouse -> Properties and all seem to be okay.
Finally, I found that the item to check is on the Synaptics Pointing Device icon on the system tray. The “Tap to Click” feature needs to be checked to make it work. After setting it properly, I enjoyed once more the tap-to-click feature of the laptop’s touchpad.