Windows 7: media server cant find ps3

So the other day we were trying to find some music on the computer through the ps3 which seems to be hit or miss some times, however the ps3 seems to find the two lap tops with no problem. So I went in to the "choose media streaming options for computers and devices" and removed the unknown devices thinking that like any other wireless or blue tooth, that they would be discoverable again and guess what..... they dont show up. This is extremely frustrating. So is there anyway to have this show up all the time on the ps3. Also we have playon and that doesn't always work either. I think that if I can get a more consistent connection between the two that play on will work as well.

Any advice is well received

You didn't mention which media server software you're using to stream your media to your PS3.

Try using this great and free alternative instead, it works great for me on all my computers:-

PS3 Media Server

Im using win media play 12.0.7

also I have gone through the stream dropdown to allow all networks and it is not showing up in there. It did show up there before I removed it like an idiot. I just want it to show up again. I have shut down and unplugged both to no avail.