Install the UnxUtils package from http://sourceforge.net/projects/unxutils/. (Or Cygwin if you're feeling ambitious.) That will give you the
which command, which you can use to determine exactly where that
java is running from. Make sure you do
which java.exe and not just
That will let you figure out where it's installed, and from there you can probably infer which distribution it is and how to uninstall it. The output of
java -version should tell you who produced it, too, along with that version number. (Though the version "1.6.0_27b" pretty much means it's Sun/Oracle's.) Once you find the installation, you may be able to run an uninstaller from there, or you may be stuck manually removing the files and PATH entries.