There exists many kinds of 'temporary' files that all have in common that they steadily increase in number and thus slowly eat up your hard disk space. Some programs use temporary files to hold intermediate data but do not delete them after program shutdown (e.g. just take a look in your WindowsTemp directory where many such files end up). Many setup programs are prime examples of this. Other programs keep producing lots of unwanted log files. Yet others automatically create backup files of edited documents. Internet browsers create a lot of cache files, 'cookie' files, history files, et c, et c.
The problem is that if you don't clean up such files periodically, your free disk space will slowly but steadily shrink and it will be more difficult to find the files that you do want because of all the junk littering it. If you are really unlucky, Windows may even crash because it hasn't got enough space for its virtual memory swap file.
The solution? CleanDisk will help you automate the task of removing most such unwanted files. Using a very easy-to-use three-step process it will quickly scan your hard disk(s) for unwanted files and assist you in deleting them! It's as easy as that!