HeavyLoad is a freeware application designed to stress all resources of a system such as CPU, RAM, Hard Drive, Network and the Operating System. Why would someone want to do this? To test to see if a computer will run reliably under load. This is known as a “burn in” by system builders and its useful to run on new computers before they are used in a live enviroment.
The way HeaveyLoad stresses a PC is by writing a large test file to the temp file, allocates physical and virtual memory and draws patterns in its window.

Screenshot:

As you can see here, its maxing out my CPU and I am losing free memory

Downloads:
Download from Official Site - 1.55mb