Windows Home Server only streams supported media to devices on the local network. To stream your videos you could install some third-party tool, such as Orb. Doing so is technically unsupported, because it requires
installing the software from the server desktop, but a number of users (here and elsewhere) have done so. Also, you will not be able to access your streaming media through the Windows Home Server remote access web site, as Orb doesn't integrate with that
site. (Orb includes it's own way of accessing media from afar.)
For assistance with configuring Orb, you would be best off with their technical support, forums, etc..
I'm not on the WHS team, I just post a lot. :)