How to really clean up computer

is there any free software out there to clean up a computer very good all i found are ones that cost money i have been told that there is a free one out ther that will clean every thing

You might be thinking of CCleaner, http://www.ccleaner.com/. The site seems to be down at the moment. Just check it later.

Advanced system care is another good one here http://www.iobit.com/ there is a free as well as a paid upgrade.