To run SunThink!, you must have Scilab installed on your computer. Scilab is a free, open source platform for numerical computation. It is available for download for Windows and other operating systems at www.scilab.org. (The current version of SunThink was designed with the 5.2.2 release of Scilab, and it has only been tested with this release.)
Once Scilab is installed, right click on the SunThink.sce file located inside the downloaded SunThink folder, and select the 'Run with scilab' option to load SunThink!