Can't install Elasticsearch - Win 7, Java build 1.8.0_45-b15

Downloaded 1.6.0, ran elasticsearch.bat and received the JAVA_HOME environment variable must be set. What do I need to change to install?

Are you asking how to set the JAVA_HOME environment variable? Find a piece of documentation that describes how to set environment variables, and use that information to create a system-wide variable named JAVA_HOME that contains the path to where your Java VM is installed, typically C:\Program Files\Java or similar.