JDK 6 does include JRE but I'm not sure what else it has

Grandpa's been running Vista for quite a while & he's used the JRE, so if I were you, that's the one I'd go for.
http://www.gnutellaforums.com/showth...ght=vista+java

I don't run Vista. In my XP, Java is listed in Program files but not in All Programs from the start menu. Try going to Control Panel (if Vista has that option) > Add/Remove programs...see if there's any Java there.