How do I persuade Windows to use the JDK instead of a JRE?
This question has been asked before, here and elsewhere:
How do I set the default Java installatio
There's an additional factor here; in addition to the java executables that the java installation puts wherever you ask it to put them, on windows, the java installer also puts copies of some of those executables in your windows system32 directory, so you will likely be using which every java executable was installed most recently.