How to tell what version of IIS you are running
In most Windows applications, the version number is listed under Help > About. For some reason, IIS Manager is an exception. There are significant differnces between versions of IIS, so it’s crucial to know which one is on the server.
Look for it in the right pane of IIS Manager, under the Version column. The column may be obscured if you keep the window rather small, as I usually do.