I came across this freeware that the distributor (systweak) claims had good reviews from pcmag and cnet. I downloaded and gave it a try: I started a complete scan with Advanced System Optimizer, including external hard drives that contain many very large .rar files archives. I noticed that most of the scanning involves a folder c:\documents and settings\user\application data\systweak\advanced system protector\rar where the archives appear to have been unpacked into. I am not aware if other tools also create copies of archived files on external drives on the main system drives and I consider this a major flaw. There should be a setting to control the copying of archives and determine if and where they get unpacked to.