have you enabled file sharing on the XP computers? To test it, use net view \xphostname.

Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net 
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com 
 We have a network with 2 domain controllers, 2 win200 pro workstations, and 3
 XP machines, one on SP1 the others on SP2.  The servers and win2000 pro
 maachines show up in my network places.  The XP machines do not.  The
 firewall is off and the machines are not hiding their presence.  All
 workstations are in an OU with a common GP applied.  I have run dcdiag on the
 master server and it is clean.  Both DNS and DHCP look fine. I have run
 "browstat status" on both servers with the following results:
 Status for domain FISHERS on transport
 \Device\NetBT_Tcpip_{07A56C51-B1E3-4CF1-8B15-473DFE8EADFE}
     Browsing is active on domain.
     Master browser name is: S1
         Master browser is running build 3790
     2 backup servers retrieved from master S1
         \\S1
         \\S2
     There are 5 servers in domain FISHERS on transport
 \Device\NetBT_Tcpip_{07A56C51-B1E3-4CF1-8B15-473DFE8EADFE}
     There are 2 domains in domain FISHERS on transport
 \Device\NetBT_Tcpip_{07A56C51-B1E3-4CF1-8B15-473DFE8EADFE}

 Status for domain FISHERS on transport
 \Device\NetBT_Tcpip_{EDC9144D-0ED6-4429-B018-FF86B033B2F1}
     Browsing is active on domain.
     Master browser name is: S1
 Could not open key in registry, error = 5        Unable to determine build
 of browser master: 5
     \\\\S1   .  Version:05.02  Flags: 84122b NT MASTER CONTROLLER
     2 backup servers retrieved from master S1
         \\S1
         \\S2
     There are 5 servers in domain FISHERS on transport
 \Device\NetBT_Tcpip_{EDC9144D-0ED6-4429-B018-FF86B033B2F1}
     There are 2 domains in domain FISHERS on transport
 \Device\NetBT_Tcpip_{EDC9144D-0ED6-4429-B018-FF86B033B2F1}

 Net diag produced the following message:

 Global results:
     [WARNING] You don't have a single interface with the <00> 'WorkStation
 Service', <03> 'Messenger Service', <20> 'WINS' names defined.

 In addition the WINS management console says it can not find a WINS server
 but the service is runnig.

 Any help would be appreciated.
 Yhanks, Robert