Could you please provide us more information about the Media Streamer!, Does the device has any IP Address (or) do you have any application for the media streamer installed?
The media streamer is a Western Digital WDTV Live HD Media Player, connected to my network using a Buffalo Airstation Nfiniti Wireless-N WiFi dongle. So it does have an IP address. I can see it on the network, and can transfer files between it and my laptop.
I am trying to access it using the 'Play To' function in Windows 7. The application software is Windows Media Player 12.
Looks like there might be some ports for this "Buffalo Airstation Nfiniti Wireless-N WiFi dongle" which has to be opened in McAfee Firewall.
However, you can try the following:
1. Open McAfee Security Center> Click on Firewall> Settings> Connections> Add the IP Address of the device over there and add them as Home
2. You may also check out this web forums in order to findout whether we need to open any ports for the WiFi dongle