well, nothing else works so you either need to find a different bit of software or get a mouse with a middle button/scrollwheel. all my mice have a scrollwheel that clicks down for 'middle button', havn't seen one without this for many years. alternate software includes but is not limited to planet-cnc control software http://www.planet-cnc.com/ OpenSCAM http://openscam.com/ NCPlot 1.2 http://ncplot.software.informer.com/1.2/ (latest version is not free) all of the above can be integrated into SketchUcam by reading the help section entitled 'Change Gcode plotter' in the menu at top right of the help page. Get to the help by clicking the big blue question mark in the toolbar. In fact, as a newcomer, you should read all of that before doing anything else (-: