You're much better off creating a little command-file to set your development environment. Start by editing a setenv.cmd file that contains the following:
set JAVA_HOME=c:\my\java\bin\dir
set CLASSPATH=.;c:\whereever\Acme.jar;c:\other\class\files
Now, before you start devloping, just type 'setenv' from the command-line.
You should be ready to go!
This is a good starting point for building your development environment.
Hope this helps.