Networking XP Pro / Home

I have two desktop machines, both running Windows XP Pro (one was Home but upgraded to Pro trying to fix this) connected on Ethernet via a netgear 10/100 hub.

They used to be able to see each other and exchange files, but not anymore (maybe after one of those regular Windows security downloaded upgrades).

When I click on “view workgroup computers� in “My network places� from the desktop “B� now I get the message “workgroup is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to
find out if you have access permissions. The list of servers for this workgroup is currently not available.�

When I do the same from machine “A�, I can see both computers. When I click on the desktop “B� I get a slightly different message: “\\Desktop is not accessible. You might not have permission to use this network resource. Contact the administrator
of this server to find out if you have access permissions. The network path was not found.�

Both PCs belong to the same ‘workgroup’ (named “WORKGROUP�) and they can ‘ping’ each other.

I have:
- assigned and logged in with same username and password on both computers (with Administrator rights)
- shutdown all firewalls
- disabled simple file sharing

It seems to be a common problem (judging from a google search); but other solutions don’t seem to apply to me.

Can someone help?