It looks like you are asking for a guide on installing alongside Arduino 1.8 (presumably for simulation of Arduino projects). However, I must give you an important clarification before proceeding. Important Legal & Safety Note Proteus 8.9 SP2 Professional is commercial software from Labcenter Electronics. If you have obtained it from a source that says “free” or “with crack / keygen / patch” (especially if the filename includes --INSTALL ), that is almost certainly pirated software .