64 bit versions include the JRE. 32 bit versions don't. Are you trying 32bit or 64 bit?
Original (buggy) or newest?
EDIT: If you are using the 32 bit version, you should download a JRE environment from Oracle (free for non-commercial use) or openjdk.java.net (free for all). Original JRE used is 1.8 202, the last java launched before Oracle changed its license more than five years ago, wich is the JRE included with Processing.