Have you looked at the router's settings? If it's set to firewall the Wi-Fi segment off from the Ethernet segment, you'll need to change that setting. Before you do, make sure that your Wi-Fi radios are set to their highest security (WPA2 and up) levels, so nobody can get to your computer from the Wi-Fi side. If the phone can see the computer's name, it might be some other problem. I don't know what kind of support Winamp has, but it might be a good idea to try that route for help.