We have small network having 5 computers(XP professional for sever and win 2000 professional for clients), we have developed a workgroup to share internet and files.From a week its happening that computers are not visible to other users on workgroup.
One worst thing is that network card donot work properly, once they work fine but on the other time they will say "network cable unpluged". But the cable was in, and if u restart it 4 or 5 times then there is a chance that it will be okay. But it did not show any computer in workgroup except itself.
One more thing that is it a good habit to allocate IP addresses dynamically, or give them manually to all comoputers attached.