I have had this recurring problem several times. I have 4 networked computers at home, all XP Pro SP2 with all the updates. Using 'Workgroup' and IP addresses 192.168.1.100 on up. I do a fresh Windows installation, go through the Network set up, turn in file sharing and share the drives. All the normal stuff. Everything usually works, at least for a while. Shortly after, my network will start break down. My main computer can see and access all others. But other computers can't access it. Or vice versa. Get access denied errors. Or the computer will be completely "invisible" to others. My NAS computer might be only able to send data from it to others. Switch to main computer, can't read from NAS. One way street. I go back through the network setup wizard. It may fix it, usually doesn't. Sometimes everything might work again for a few days, then slowly break down again. Not using Windows firewall, or any for that matter (up to this point of getting set up). No viruses or spyware. I get totally baffled over it. The really frustrating thing is that I manage 30+ computers at work and never have this problem. I am nLite'ing the cds, but only removing the basic stuff; nothing of network importance. Any and all advice is welcome. No one has been able to really nail down the problem.