Cannot remove J2SE Java Runtime Environment

[frankarl]

The original removal failed, the J2SE does not show anymore under "add
remove programs" but when I try to reinstall J2SE the installation
program tells me the Runtime Environment is still there.

I assume I have to get into the registry to clear this, but cannot find
the right place.

Anybody can help ?? I have to reinstall J2SE. Runnning Win XP Home

Thanks