Java

Download and Install Java SE (Download JDK)

Win+Pause -> Advanced system settings -> Environment Variables

Edit Path and add after string: ;C:\Program Files\Java\jdk1.6.0_24\bin\

This works then:

javac Example.java
java Example

NetBeans IDE

Edit /etc/netbeans.conf and link to JDK location
e.g. netbeans_jdkhome="C:\Program Files\Java\jdk1.6.0_24\"