What kind of server is running there?
windows 2000? NT?
Make sure you're not using any 'extra' protocols in your network settings. Go to start, control panel, internet and network connections, network connections. Right-click on your local area connection (you should have at least one), properties.
Check the components box here, unless absolutely needed, you should have only
Client for MS networks
File and Printer sharing
TCP/IP
If that's all you have, then highlight TCP/IP, properties, advanced, DNS tab. Make sure you have the proper DNS entries here, unless you get your IP address from a DHCP server. In that case, you'll also get DNs entries as well.
Also, you can check to make sure your network adapter is running at maximum speed. odds are that it will be 10/100 MB with auto-detection, but you can always check. To check that, go to start, control panel, system, hardware tab, device manager, and look for your network adapter there. Double-click on it, then go to advanced, media type. It should be set to auto.