I'm experiencing a similar problem. For example, right before I came to this forum, I had CCleaner do a run: To Be Removed: 51.4MB Removed: 814.5MB I've also noticed that during "Analyze", CCleaner is not(?) doing an analysis of the custom folders I have set up for deletion. However, in the few folders I do have set up, there was not 750MB of data (for the previous example). I am using CCleaner 1.40.520 and WindowsXP Home. Ihave CCleaner set up to do a 7-Pass secure file deletion. As far as checkboxes go, I have the "default" boxes that are established when CCleaner is installed, and I also have "Custom Files and Folders" checked.