For Windows 7, I\'ve installed JDK in both 32 and 64 bit versions. The versions are 8, update 20 for all four installations. http://www.oracle.com/technetwork/java/javase/d
Can you verify JAVA_HOME is set to C:\Progra~1\Java\jdk1.8.0_20,
C:\>echo %JAVA_HOME%
Also, verify java command is available,
java -version
Reference
Check if JAVA_HOME is present in environment using batch script
If JAVA_HOME is not set, please follow the steps provided here - How to Set Java Home in windows
Summary ,
Enter the variable value as the installation path for the JDK.
(eg. C:\Progra~1\Java\jdk1.8.0_20).