System Tracker - Show/Describe/Control active processes, free.
System Tracker is a small yet powerful utility that gives complete control over all active processes on your computer. Not only does it audit your machine and present all active processes, System Tracker shows all registry activity in real-time, shows what programs are set to automatically start by location, and also enables users to set programs to not start. Easily access the large, detailed, online database of process descriptions. All free.