Hi,
Some things to check on the workstations and server.
1. Check the power settings in screen properties, may be hibernating.
2. Some NIC's have power saving functions, check the properties in Control panel/Networking and check the adaptor settings.
3. Also check WOL settings (Wake on LAN), may be going to sleep.

>Neil:
>
>Thanks for not giving up.
>
>No, no COM or KeepAlive.
>
>I did check the server event log and found the following:
>
>o WinHTTP Web Proxy Auto-Discovery Service has been idle for 15 minutes, it will shut down.
>o WinHTTP Web Proxy Auto-Discovery Service suspended operation.
>o WinHTTP Web Proxy Auto-Discovery Service enter the stop state.
>
>These entries are about the time the workstations went down.
>
>Not sure what WinHTTP Web Proxy Auto-Discovery Service is but will look it up.
>In the mean time, do you have any ideas on this?
>
>TIA
>
>
>
>>Hi,
>>Are you using COM ? KeepAlive ?
>>
>>Are there any entries in the Event logs of the Server or Workstations.
>>
>>>Hi Neil:
>>>
>>>Thanks for you reply.
>>>I tried diabling autodisconnect (ran the command and it said "done").
>>>
>>>It still happened all the workstations, except 5, got disconnected from the network at once.
>>>5 stayed connected. Strange ...?
>>>
>>>Thanks for your time though :o)
>>>
>>>Mal
>>>
>>>>Hi,
>>>>Disable autodisconnect http://support.microsoft.com/default.aspx?scid=kb;en-us;297684&Product=win2000
>>>>
>>>>>HI:
>>>>>
>>>>>I have 20 workstations connected to my Windows Server 2003 server.
>>>>>
>>>>>If I leave a workstation connected buy idle for ... 1 hour, the workstation geta disconnected from the network. I would have to reboot the workstation in order to use the workstation on the LAN.
>>>>>
>>>>>The other problem I'm having is: At about 11:00 PM every night, all of the workstations gets cut off from the network. Again, I'd have to reboot all of the workstations to connect into the LAN.
>>>>>
>>>>>I do not have any restrcitions as "hours of use" on any of the workstations.
>>>>>
>>>>>I there some where in Server 2003 that I can check to see if the server is logging any of the workstations off?
>>>>>
>>>>>TIA
>>>>>
>>>>>Mal