Synaptics touchpad Vista error

I recently had to work on two Vista laptops where the touchpad had stopped working. The laptops were from different manufacturers, but both used a Synaptics touchpad. 

The device manager showed a “Code 10” error for the touchpad in both cases. No amount of driver uninstalling, reinstalling, driver roll back or praying got these touchpads to work. It appears that a driver update from Windows Update killed the touchpad in both laptops. 

Eventually I solved the problem via Service Pack 1. On the first laptop installing SP1 fixed the issue. On the second, which already had SP1, uninstalling it fixed the issue (I then reinstalled SP1 without any problems). So if your touchpad has suddenly stopped working and the device manager shows a problem with a Synaptics device, try installing or uninstalling SP1.