Most conversations about unwanted double-clicks focus on mice, with their worn switches and chattering buttons. But laptop users face their own version of the problem. A touchpad that opens files when you only meant to select them, drags windows unexpectedly or ignores your double-tap can be just as frustrating. The causes are different from a mouse, and so are the fixes.

How touchpads detect taps

A touchpad does not have a mechanical switch under each finger. Instead, it senses changes in capacitance when your skin approaches the surface. Software then decides whether a touch was a tap, a drag, a scroll or an accidental brush from your palm.…