Step 7: Install Java

Install Java
Most people already have Java installed, but if you don’t, follow this step.

1) Go to www.java.com/download.
2) Click “Free Java Download”.
3) Click “Agree and Start Free Download”.
4) Depending on your opperating system, a different version of the file will download.
5) Follow the onscreen instructions to continue installing the software.
6) Click finish and be done installing.  Continue on to the next step to set up a miner.

Source : http://www.instructables.com/