Alessandro A. Garbagnati
Check out this document:
How To Setup TOMCAT 4.0.1 on Windows 2000 with IIS and NT Service
This great documents shows how to get Tomcat 4.0.x to work as an NT service. The creator has used the Tomcat 3.3 documentation page regarding this topic, making few updates to the wrapper.properties file, in order to make it working with the latests (4.0.x) version.