Q: Where do I find the name of my server?

I need to watch videos that my biology professor uploads using QuickTime, but my Mac tells me I do not have the proper software. I clicked "tell me more" and then downloaded an app according to the video's extension (.rm). The app was RMS Viewer, when I open this app to use it I need to know the name of my server, how do I find this ? Or is there another app would allow me to view these videos?