Hi. I have 3 PCs and a couple of printers on my home network configured with fast Ethernet (100mbps) over CAT5 cabling, and they all work fine on the internet with DHCP addresses provided by a D-Link router connected to a cable modem. Until recently, I could map to shared folders and printers on the network, but that is no longer true. The D-Link router does have a firewall, but that was true before the problem began. The only thing I can think of that might have changed at around the time the sharing problem began was that I installed "Trend Micro Internet Security (with the personal firewall turned on)." I installed SP2 on one of the XP Pro machines, but again, the problem preceded this installation. I'd really appreciate any advice on this matter since sharing folders and printers is very useful to me.