Win NT Workstation

I'm going to assume that you have verified that the server service is set to automatic in startup (control panel - services) and that it is using a system account. I also assume that you have tried to start it from there as well.

If it is still giving problems, try reinstalling the most recent service pack on the system.

If that fails, remove and reinstall the server (network icon in control panel), and then reinstall the service pack.

If that happens it means that there is another PC on the network with the same name.
Look for this article in the Microsoft Knowledge base http://search.support.microsoft.com/kb/c.asp

Q177497 - Server Service Fails to Start at Startup with EventID 2505

Cheers ....

I'm not sure if this will help you but I have had this problem when running service pack 5, upgrading to 6a did solve the problem. The message I got was "Insufficient memory to start server service" or something along those lines...
If you are already on sp6 then you may find it quickest just to reinstall the IP stack.

There should be entries in the event viewer indicating why the Server Service did not start. If it did not start because of insufficient memory or space, then installing your latest service pack should resolve this issue.
If there is a device, such as your NIC not loading then you need to troubleshoot that device. You don't indicate anything else to help in assisting you.

To remove the service (and not the network icon which you cannot remove from control panel without significant problems) - open control panel and double click on Network. Click on the Services tab. Highlight Server and click the Remove button. When it is removed, click the Add button, find server and click OK.

When that is completed, click OK and let the system reboot. Once rebooted, login and apply the latest service pack (6a). Reboot and you should be taken care of.