Problems seeing Workgroup Computers

Is Norton Antivirus 2005 installed on these machines? I ask because one: this is a possible reason and two: after running the Network Setup Wizard Windows Firewall (SP2 only) will re-enable, not always but I've seen this before thus denying some, but not all, network connections.

Second Question: What network topology exactly are you using; Star, Peer-to-Peer, Internet Connection Sharing? The Netgear FS105 is a network switch which you would use if one of the computers is the ICS host.

Third Question: If you are using the FS105 as a swicth did you run the Network Setup Wizard on the ICS host first, (the one connected to your modem)? This you would need to do and then run the Wizard on the client machines.

Suggestion: Lose the switch and establish a Peer-to-Peer network by placing a Linksys Router/Firewall between your Internet connection and your client machines. Fits like a glove, less filling - tastes great :) Hope this helps!

Is each PC getting IP information via DHCP or are you hard coding that on each client?

Does the DNS server have an A record of the clients?

There is no server, IP addresses are manually set on each computer.

Check if you are using simple file sharing or not on both PC's and make sure it is the same on both (You check this by opening My Computer or Explorer and choosing Folder Options from the tools menu, then going into the view tab to see if this is checked or not).
Double check that the XP firewall is not still enabled on either PC also.

Just a few thoughts:
Is the workgroup exactly the same on each computer, even to case?
is one XP computer to act as a server?
That computer must have user and password identical to each connecting computer.
You said you set up IP numbers, so i giuess you have static IP numbers. They must be consistant with your Router. For example if the router gateway is 192.168.0.1 then an acceptable IP number to connect would be 192.168.0.2 through 192.168.0.255, both with a Mask of 255.255.255.0
Peter

Do you have any antivirus (security) software installed? I've found it necessary on occasion to uninstall Antivirus software (Norton, McAfee), setup the network, then re-install antivirus. Even with the computer firewall turned off, the antivirus software conflicts with communication and prevents "seeing" other computers in the workgroup or LAN. Note: In one case, the antivirus software had been deleted improperly and I had to re-install it in order to UNINSTALL it properly. Hope this helps.

sounds like you are almost there so i would look for gotcha. like, did you try swapping the ports on the switch, bad computer and good computer? maybe the cable too.
if it is not a physical connection problem,
the the highest prob is what everbody saying: firewall. check each pc and look at the network connection it is using and make sure doesn't say 'firewalled'.
have you explored using the Network Setup Wizard in control panel on one xp home box. it can help you set them all up.
when troubleshooting these connections, i start from bottom. first check for link light. then use ping from command prompt to see if i can ping whatever is out there to be pinged, in your case the other computers. in some cases, an internet router...
wonder what sp xp is. wonder if you are logging in with same account on all pc's wonder if that account is admin. you will need user accounts on each pc all same usernames and passwords. that is one example of stuff Network Setup Wizard will help you get set up...

First thing I would do is to check to see if I can ping the other machine. This will tell you straight away if the problem is physical or if it is a software config problem. If you can ping both ways by I.P. address {I.E. machine one pings machine 2 and then machine two pings machine one}. Then ping using the machines NetBIOS name. Also make sure the firewall is off, also remember that after you complete the network wizard you have to share a file or you won?t be able to browse. Hope this helps.