The HDHomeRun Prime will show as a DLNA device named "HDHomeRun DMS"
Some clients may show three "HDHomeRun DRI" devices - these are used by WMC and should be ignored when using a DLNA client.
If you see "HDHomeRun DRI" devices but do not see the "HDHomeRun DMS" device then the HDHomeRun is not enabled for DLNA. Make sure you are running firmware version 20130328 or newer.