How do I get ps3 to connect to media player on my laptop?

I have dell inspiron 9400 with vista and norton 360 v2. In norton I have allowed windows media player, I have turned on media sharing. how do I get it to find my ps3. My ps3 keeps saying it can't find any media servers. Do I have to go through a router or can I do it without one? This is beginning to bother me big time.

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