Help - No file sharing over network Win XP/Win98

Hi,

I have three computers on a network. One with WinXP the other two with
Win98. I can connect to the internet fine with the XP computer but I cannot
file share. I can't even see the shared folders on the XP computer when I
bring up "My network places" even though the sharing is turned on. I cannot
see any of the other computers on the network either. I have TCP/IP
enabled. I've run the Network Setup wizard on all the computers. The Win
98 computers "see" each other fine on the network, just not the XP. I
don't have the foggiest idea how to fix this.

Thanks for any help!

David