Do not download anything labeled "Grandma2 on PC 31 25." It is almost certainly a scam or virus.
The installation wizard will guide you through the process. Read and agree to any terms and conditions, choose your installation location, and select any additional components you might want.
The software is designed to run on Windows PCs and notebooks.
The combination of numbers ("31 25") does not correspond to standard versioning (e.g., v3.1.25) for any known "Grandma" software. The most famous "Grandma" in PC software is (a professional lighting control console software), but its current versions are named sequentially (e.g., v3.9.60). There is no "31 25" build.
grandMA2 onPC Version 3.1.2.5: Essential Guide The grandMA2 onPC software is a professional lighting control solution that brings the powerful features of a grandMA2 console directly to your computer. Released on January 9, 2015