Norton corporate edition not updating on my win 2000 server

HI ALL,

I HAVE A LAN WITH OVER 50 WORKSTATION,I HAVE A LOTUS NOTES MAIL SERVER AND A WIN 2000 SERVER.

WHEN NORTON ANTI-VIRUS DEFINITIONS ARE BEING UPDATED DAILY,MY WINDOWS 2000 SERVER IS THE ONLY MACHINE THAT IS NOT BEING UPDATED.

ANY REASONS