In Control Panel, Add or remove Programs, I have what appear to be three Java programs: 1) J2SE Runtime Environment 5.0 Update 10 (Size 145MB) 2) Java(TM) 6 update 2 (Size 133MB) 3) Java(TM) SE Runtime Environment 6 Update 1 (Size 159MB) These files are quite large, is it necessary to keep all three? Doesn't this slow down my system? Thank you