I'm supporting a 4 computer network: 3 have 98, one has 2000 Pro. It is a peer to peer network.

Computer MAIN, a 98 machine, has the quickbooks data files on it, and the other three access quickbooks over the network.

CLIENT1 and CLIENT2 are 98 machines. They don't have any problems accessing the quickbooks data files.

CLIENT3 is the 2k machine. For the most part, it works flawlessly. But recently, their QB data file has been getting corrupted very frequently, and they have to restore the backup file. They called me out to check on the network, because something seemed fishy.

I ran a "ping test" on all three CLIENT computers. I ran four instances on each computer like so:
"ping main -l 65500 -t"
so that each machine had four sessions open, pinging MAIN with 65500 byte packets.

CLIENT1 and CLIENT2, as suspected, pinged just fine, with only about 3-5% packet loss over about 15 minutes.

CLIENT3 (win2k box), pinged fine for about 5 minutes, but then took a major downswing, losing long strings of packets. After about 15 minutes, the loss rate reached nearly to 80%.

Here is what I have tried:
1. Replace NIC
2. Replace hub with 10/100 switch
3. Replace network cable

None of these provided any help.

I am currently downloading the Win2k service pack 2.

Does anyone have any ideas what could be causing this phenomenon?