Periodic Network Breakdown

I have three computers running on a private home network. Two machines run Win98SE and the other runs Win2k. Every now and again the network collapses so that no network connections can be restored on startup, the local shared printers cannot be used and the ICS is unavailable. I have spent fruitless hours reinstalling drivers and replacing and moving cables in case of a bad connection and am fed up with the whole lot.

Can someone help me??
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I would assign a static address to you 98 machines for the purpose of diagnosing which element is the problem.
When the network "goes down" you'll then be able to use the 98 machines, if they can see one another you can focus you efforts on the ICS machine.
If not, you can have a look at your switch or hub.
( If that fixes the problem, likely the ICS dhcp was hosed.)
When this happens take a look at the ICS inside interface and see if it has correctly negotiated speed and duplex with your switch or hub, if there is a mismatch consider setting the nic to half duplex and 10 or 100 Mbps depending on your equipment.
I'd also consider loading a sniffer on one of the 98 machines to see of something's infected and using up your bandwidth.
I'd also check for spy/adware (I like spybot), viruses, etc.

Try replacing your switch or router-switch with a spare (or try to borrow from a friend) & test it out for a few days to see if the network stabilizes. If it does, then it's either fried, or as suggested by chicagoan, try manually setting the speed & duplex settings on your PC NICs.

Btw, what type of switch & NICs do you have ?
How, exactly, is your network configured?  Is the Win2K running ICS and hooked up to your ISP, while the 98's are "behind" the Win2K, on a switch or hub?  Are you using DHCP for your private addressing?  Can you give more detail on what happens when "the network collapses?"  What kind of Internet connection are you sharing via ICS?

I agree with chicagoan that you should check for spyware, malware and adware.  

I also recommend that you go to a site that has an online virus scan, like Trend Micro's Housecall and run it against all 3 of your systems.  It's not a bad thing to do once in a while in any case, but since you keep having these problems, it would be a very good thing to do, just to be sure.

Do you have an antivirus running, especially on your Win2K box, with virus signatures kept up-to-date?  Do you have your Win2K box patched to current, with the latest Service Pack as well as all of the applicable security hotfixes?  Are you running a software firewall on your Win2K box, to further protect your private LAN from the Internet?
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PlyderAuthor Commented:
The ICS host is the W2k machine which connects directly to the ISP. The network card on the w2k machine then connects to a hub as do the other two machines. Usually all things run fine but every now and then the network crashes and I don'n know why.

I am writing this quickly as I have just got these three messages and now intend to run spybot etc and check what chicagoan reccomended. I will get back after the weekend if you guys can hold on till then
What are the error messages you get ?
PlyderAuthor Commented:
OK sorry for taking so long as things have been mad lately.

I changed the connection cables from BNC cable on the two 98 machines to CAT5 cable and connected directly to the hub. The computers can see each other now nut the ICS has been knocked off and when I try to reinstall the ICS it says - unavailable please finish installing your network - this is on the 98 machines

I removed all the network cards and modems from the network reinstalled them, the comuters can still see each other but I still cannot install ICS.

I have installed and run spybot but nothing of significance was found on any of the PC's (nice program by the way :-)

why is it not allowing me to install the ics??

PlyderAuthor Commented:
Help I still cannot seem to install the internet connection sharing on the win98SE machines as it has been knocked off. Previously the first win98 machine was connected to the win2K machine and then to the hub via a BNC cable, the other win98SE machine was connected directly to the hub via CAT5 cable. All machines can see each other on the network and share files. The win2k machine is the one that has the modem attached to it and the network uses internet connection sharing to share the internet connection. When i go into the system components in control panel-add/remove progs, and select internet options, the internet connection sharing checkbox is unmarked. When I try to select it the computer comes up with an error message saying that the network is incomplete and that i should finish installing my hardware. I have noticed that there is a network card adapter that is not usually there and i have not seen it before. It says it is an existing ODI adapter, should this be there?? when I try to install it it is looking for Novelle disks which i do not have?????? As far as I know my network is complete so what is wrong?

Please go into your Network Neighborhood Properties and list all clients, protocols and adapters you see.  You may have to do a reinstall of some or all of your networking "pieces" and probably need to uninstall some and leave them uninstalled.

If you have no NetWare in your environment (which I find unlikely from your description so far) you shouldn't need whatever it is looking for as far as Novell disks are concerned.

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