New to Java

Hello,

I have a very messy java situation here.
I see three J2SE runtime environment 5.0 (updates 2, 5 and 6), and two java runtime environment standard editions (1.3.1_13 and 1.4.2_08), in Add/Remove programs of the control panel.
My problem is that many java programs are not running. I install them and they do not run. I try the same program on another computer and they run fine. So I tried uninstalling all the javas I see in the control panel. However, when I try removing them, they always crash/freeze during the uninstalation process, and never actually get removed.
Is there any way to do a complete java cleanup of all folders/files/registry entries/etc that all versions of java have created so that I can then install one fresh clean java version? If not, is there any way to completely remove the existing versions one by one?

Thank you.