Server not showing in My Network Places

This is driving me crazy. I have a file server (masterserver) and for some reason it is not visible under My Network Places. I can see every other computer on the network though. I am able to get to the server by typing \\masterserver in the address bar, but it is a pain when users are trying to get to the different shared drives and i have to assist them in doing so. Also, we have a few Macs and they are not able to see it.