Introduction & Installing

Install Java Development Kit (JDK)

Download JDK 1.8

http://www.oracle.com/technetwork/java/javase/downloads/jre8-downloads-2133155.html

You must select the correct software (32/64 bit) depending on your platform
After downloading the software, install it completely and set PATH.
                     
                 Control panel→System→Advanced→Environment Variables

Set path to the bin folder where the java is installed
                      C:\Program Files\Java\jdk1.8.0_45\bin;

Now your computer can run java applications

You can check it like below in Windows platform

1.Go to start menu
2.Type cmd(command prompt)
3.Type javac

4.Press Enter

If you can not understand please watch this video

Now you can view a list like above.If it does not appear you have to follow your installing steps again