Windows 7: AV receiver and WMP12

Hi,

I am a noob, great looking site. I have done a search and cannot seem to come up with a solution.
My problem is with streaming media over my home network. I am running Windows 7 Ultimate and my son's computer is also running Windows 7. I have a Yamaha HTR 6295 network receiver.
My Computer and the receiver are hard wired to the router and my son's is wireless.
The receiver shows my son's computer on it's server list, but not mine.
When I go into My Network Places, it shows the receiver as a media device.
Am I missing something in the settings on my computer? I have enabled media sharing, shared folders, etc.

Please Help!

PS Sorry if this already been covered