Simple example for how to set JAVA_HOME with setx.exe
in command line:
setx JAVA_HOME "C:\Program Files (x86)\Java\jdk1.7.0_04"
This will set environment variable "JAVA_HOME" for current user. If you want to set a variable for all users, you have to use option "-m". Here is an example:
setx -m JAVA_HOME "C:\Program Files (x86)\Java\jdk1.7.0_04"
Note: you have to execute this command as Administrator.
Note: Make sure to run the command setx from an command-line Admin window