Make sure you have the entire developer kit (JDK) installed, and not just the runtime environment (JRE).
Download the above file and run it.
After you download your compiler, you need to have PATH gone through your compiler folder.
From Search file, you locate your
java.exe file first,
for example, C:\Program Files\Java\jdk1.6.0_23\bin
Right-Click on "My Computer" / Click on Properties.
On the end of Variable value add a semicolon then your folder of java.exe file like
In the first field, enter "classpath" and the second field enter a single period.