Server Maxes out at 100%-then drops!

Rural school district with Novel Network. W2000 Server is raid, Inoculate E Trust, approx. three years old. Novell 5.1. Have eliminated any “broadcasting” programs. Recently purged records and freed up alot of space.
Today, server froze. Downed and still intermittant high utilization, but able to log in, etc.
Any suggestions?