Octave 4 installer doesn't detect JRE at install time

[Will]

Hi all,

Today I downloaded and installed the Octave 4.0 release from here 
https://ftp.gnu.org/gnu/octave/windows/, but got a warning about not 
detecting the java runtime environment. This was true - it wasn't 
installed, so I went and grabbed the JRE and JDK (64-bit, version 8 
update 45), rebooted windows, and tried to install Octave again. But, 
the installer still threw the warnings about not detecting the JRE. I 
accepted all the defaults during installation of the JRE and JDK, and 
installed in the standard path (C:/Program Files/Java/jre1.8.0_45). Any 
idea what I need to do to get Octave to detect the JRE at install time? 
The Java integration was something I was quite looking forward to!

Thanks in advance (hope I'm not missing the obvious!)

- Will