If you know that you have a 64 bit computer, you can download the 64 Bit versionR-Instat 0.6.5 Installer 64 Bit (.exe 551MB)
R-Instat is currently a Windows only application. However, it can be accessed on Mac or Linux through use of a Virtual Windows Machine.
To see the changes made since the previous version check out the release notes.
.NET Framework: R-Instat is a .NET software and requires an up to date version of the .NET (at least 4.6.1) to be installed before it can run. Most new Windows version already have this. The installation process will tell you if your .NET needs to be updated. If you need to download it, you can download .NET Framework here.
R: R-Instat includes a built in copy of R (currently version 3.6.2), which performs all data processing in R-Instat. You do not need to download R separately to use R-Instat. If you would like to know more about R see https://cran.r-project.org/.