I don’t know if I am using a client or a desktop version – how can I verify this?

Startup the software and look at the title of the application in the top left part of the title bar. If you see “Omixon HLA Twin RUO” or “Omixon HLA Explore” – you are using the desktop application. If you see “Omixon HLA Twin RUO – using XYZ server” or something similar where the name of the server is included then you are using a client application connecting to a server.