I have some legacy systems which require java runtime 6 to run. If I try to go about my business and run into a web site that uses java it will complain about the old insecure java version and recommend upgrading to v8. When I do that I find inevitably that it messes up my ability to run JRE 6 at all. Then I have to uninstall jre 8 and finally jre 6 will run again. Is there a good document on how to run JRE 8 most of the time but successfully run JRE 6 as needed? I tried specifying the path at the command line, dragging the jnlp file onto the jre6 executable adding the jre6 path to the environment and on and on. But so far 8 seems to just poison 6 completely.