Running Mathcad on Windows 8.1 64bit

I was about to download the Mathcad trial and checked the system requirements. Apparently release R2018b isn't supported for Windows 8.1. Does this mean that R2018b won't run on Windows 8.1, or does it mean that there won't be technical support? If I decide to buy a Home licence, can I install an earlier release that will run on Windows 8.1. Regards Bob Sutherland

[Walter Roberson]

I'm pretty sure that Mathcad does not have releases named like "R2018b".

If you are talking about MATLAB, then it means that it might or might not work properly on Windows 8.1, and that some problems might or might not be able to be worked around by setting Windows compatibility mode.