[jba]

- are you sure they're on the same network? make sure you're not picking up a neighbors access point on one of them. Start -> Run "cmd", at the prompt type in "ipconfig /all", confirm that subnet mask, default gateway, and dhcp server are the same on both. IP address should be different for the two also; from each try typing in "ping <other IP>". you are either going to see a bunch of replies or timeout messages.. edit: also try "ping <other maching name" if the IP address works.

- Start -> Settings -> Control Panel, Network connections. Confirm that File and Printer Sharing is listed and enabled (if you get desperate at some point uninstall/restart computer/reinstall)

- Try temporarily disabling all software firewalls. There is an XP one that you should see in the connection properties dialog from the previous step. If you have another one installed (Norton or something) disable it. It's VERY dangerous to leave like this so only do this to try to diagnose and make sure you turn back on.