Exactly right, but they're not "running" until you start em. I have several on my machine, and I often start Java programs with a batch file that sets the path and classpath to the exact JVM I want. My main work project must be on 1.3.x and my pet projects require 5.0.
You can get confusing problems when you run the install routines for different JREs. They may clobber each other in the registry and overlay each other's settings for applets in IE. I can't say just why I DONT have such problems, but holler here if you do and somebody will try to help.
A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi