Network stopped working all of a sudden

[Nuclear Krusader]

I know that this is a very stupid question that must have been asked thousands of times before, but I'm a complete noobster regarding networks so plz bear with me.

I was called today to see a network that just stopped working all of a sudden. It's a Win98/WinME network. The machines (5) can't find each other or the server for that matter. (Hmm, this server is actually just a name coz the network is Point to Point).

I replaced the hub. Nada. We tested several cables. Nada.

They had a blackout at the place yesterday, but we also tested another machine that wasn't working when the blackout happened with the same results. They have no surge protection for the PCs, just for the server. But if the NICs were fried, why sometimes the network works? Another guy had already gone when I arrived and he had taken the server to his office to check it. We tried the backup server and to no avail. Sometimes the machines see themselves but that only happens 1 out of 100 times. (so to speak)

They told me that the first time they ran the backup server the network worked fine, but then they had to change a date in an Access database and then it stopped working. I think that the prob is hardly caused by that date modification.

The AV is updated. All the PCs have the same network configuration. All have NetBEUI and TCP/IP protocols, all start the session in M$ Family and all have the HDs full shared. It's the way they tell me the network has been running always with no problems.

What could be wrong? What did I forget to do? Any ideas?

TIA for any input.

[KHT]

Have you tried booting one machine and then sytematically booting each machine separately, testing the LAN each time in hopes of identifying the problem source.

I recently had a single NT4 client with a bad NIC bring down a W2k Server. Shutting down this one machine solved a few annoying problems that had been progressively getting worse.

[Nuclear Krusader]

Thanks for the response.

Actually, it was a virus that somehow messed the configuration in the machines. All is fine now, after the virus was taken care of.