This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
If you set a JAVA_HOME parameter, then you can set all your other stuff like classpaths etc in reference to the JAVA_HOME parameter: set path=%JAVA_HOME%\bin;%path% set classpath= .;%JAVA_HOME%\lib; Now you can just switch around your JAVA_HOME parameter and all the related parameters get automatically updated.
The down side of the JAVA_HOME parameter, is that you can forget that you have it set, say in your autoexec.bat, and then you go and tinker around with your classpath, and pick up stuff from the JAVA_HOME directories, causing suprising results - so beware.
"JavaRanch, where the deer and the Certified play" - David O'Meara