[grantw]

I have a network of 10 pc's with either XP or Windows 2000 as OS connecting to a SBS 2003 Server. All of the XP machines run fine, but 2 of the Windows 2000 machines will log on but then lose connection to mapped network drives. If I try and log off and then log back on I get a message "the network request is not supported". If I then shut down the computer and turn it back on, it will allow me to log on normally. I can see all the drives, but after a period of time 5 minutes - 30 minutes it will lose connection to the server and all drives. Does anyone know why this may be happening as I don't have much hair left now

[JamesBond]

Times that I've had this problem it's been network card related; however, because you said that it's only some of the win2K machines that are acting up and none of the XP's, it sounds suspicious. I assume that all the profiles and drivers for the Win2K's are identical? If the machines and setup are the same, I would try new network cards, because this has always been the cause in my experience. After trying this I can only suggest an O/S install.

If you still have trouble try posting again with more details on the machine configuration.

Good luck

Here is a link to a number of Networking articles that may be of help:
http://www.findingfacts.com/L3/L3_1_17_18.php