2 computers are sitting in a room together..

[privymaster]

One says to the other: Hi I'm a Yamaha AV and I can go on to the internet, and also recieve Mp3's from a computer if we are plugeed into a router together. The other computer says:that will probably be me, and I have windows media player installed, so you can access all my mp3's that way,.. excitedly,..now here is the problem of getting these two "hooked up". In order for the yamaha to see the computer, I have to unplug the router and modem, turn off the yam and computer, then plug in the modem and router, then the yamaha, then the computer. If i do this the yamaha reciever sees the com puter and the can have their relationship. If the computer goes into rest, or sits for a while, or just sits dormant, it looses contact and the yamaha can't see it anymore. The only way to correct this is to begin the steps above. What can I do to solve this problem?
Thanks