Ursprünglicher Beitrag von: Chris Green ,
You said click works, but can you also move the mouse pointer around with one finger? If so, test to see if [https://support.apple.com/en-us/HT204895|other multitouch gestures] work. If any of them work you can rule out the possibility of a hardware problem. There could also be an issue with Mac OS X settings that is causing multitouch not to work properly. If you have OS X install media ([https://support.apple.com/en-us/HT201372|or the ability to create a bootable USB drive]), boot the computer off of that and see if the gestures work in the OS X installer.