By "able to use fetch on another computer" I assume you mean from a different machine being able to <fetch> the same host/URL. The DNS settings for the problem computer may not be correct; eg. it may not have any nameservers set. Try to telnet to port 80 of the URL's host from the problem computer: if it fails with "Host not found" or the like, the problem is with its DNS settings.
Thanks kai. That seemed to work. What exactly does that command do? Yes it is an NT system, actually Windows 2000. Here's the output of texis -version:
Texis Web Script (Vortex) Copyright (c) 1996-2001 Thunderstone - EPI, Inc.
Commercial Version 3.01.984682785 of Mar 15, 2001 (i686-intel-winnt)