Try this:
Open your control panel - open programs - check for java there and start it.
A window should be popping up now with java controls, update settings and the like.
Go to the tab named java and press the button to see all java runtime versions installed.
On the most right side you can deactivate the older version.
I have done this,(or the closest I can, as I am running OSX 10.9.5) It only has java 8 installed, and the latest version at that.