So here's my situation....aka PROBLEM: I have a PC running windows 2000 and a powerbook. Now wired, I have no problem sharing between the two (although, I'm still having problems sharing folders (or external drive) on my mac outside the home folder). I just got an airport express. Set up was easy...no problems connecting to the internet. However, I cannot access my windows machine from my PB wirelessly and vice versa. From my PC I can ping the airport express, and from my PB I can ping everything...router, PC, airport express, etc. I've got the cable modem going directly to the Netgear wired router, my PC is directly connected to that, as is the Aiport express. I did a search here and found that one person just typed in the IP address to make the connection, but I don't know where this is done in Mac.