How do I install Open Radioss?

have you looked here?

https://openradioss.atlassian.net/wiki/download/attachments/1016017/GettingStartedWithOpenRadiossTutorial_2022_09_10.pdf?api=v2

https://openradioss.atlassian.net/wiki/spaces/OPENRADIOSS/overview

if you have openradioss questions, it is better to ask in the github discussions for the project:

https://github.com/orgs/OpenRadioss/discussions

There are guides to running it here: OpenRadioss Confluence pages guide to running

If you have downloaded the windows executable (pre-compiled) the easiest way to run it is to additionally add the guis here: Guis for job submission in OpenRadioss (OpenRadioss Confluence Pages)