Are you running a multi-processor machine? I don't believe Microsoft made a server version of 3.1, but I could be wrong. Unfortunately, they stopped supporting NT 3.1 over three years ago.
There are two versions of Windows NT 3.1: "noname" Windows NT 3.1 ("Workstation") and Windows NT 3.1 Advanced Server. I donīt know whether they have multiprocessor support, but for sure they do not support Pentium II and higher processors at all.
See my previous post http://www.computing.net/windowsnt/wwwboard/forum/22312.html