Windows

OK, a couple of things:
1) Do you require all 3 of those protocols? If not, get rid of at least 1 of them. If you are in a routed environment, ditch NetBEUI and use NetBIOS over IP.

2) Disable Browse Master capabilities from all machines except your NT Servers. All Win98 and WinNT workstations should be changed from Browse Master=Auto to Disabled.

3) back to routing - are you using DHCP or are machines hard coded? Can you ping from machine to machine?

4) Is WINS running on 1 or more servers? You may want to initiate a scavange on your WINS server. Make sure all of your clients point to the correct WINS server.

Good Luck!

Try this:
On all the 9X machines with file and print sharing enabled, go to properties of network neighborhood select File and print sharing, go properties, highlight Master Browser and select no.
I think that the machines that have file and printsharing enabled are participating on elections for Master Browser. What happens is that if this machine becomes master browser and its rebooted another election starts, and while all of it is going on, you'll have an incredible amount of traffic in your network and the machines will have to sit and wait for a decision before they can get the word from the BDCs on who's the Master Browser.
But, then and again, I might be wrong.

Good Luck!

You didn't mention anything regarding this, but another thing you should check is that the machines are in the right workgroup. This is set in the Identification tab under network properties.

Hope this helps.

Remove IPX and NetBEUI if you are not using these protocols. Extra protocols means extra network traffice (as well as other headaches). Lastly, right-click on Network Neighborhood -> Properties -> click on the Identification tab and make sure thatthe workgroup name is the same as the name of your domain. Also, make sure that file and print sharing is enabled under TCP/IP.

When I had that same sort of problem, it
was the NIC's. Some models I could update
the drivers or add Client for MS Networks.
Others I just replaced with Intel or 3com's.
Seems if I remember correctly, it was a
kingston card that was my problem.