Files that are deleted in Windows are not really deleted–just the links to where the files are located on your hard drive are removed. Despite allowing you to use the space for other files again, the actual information is still lurking on your disk space. In other words, a knowledgeable computer user would be able to locate enough information to restore a file you wanted to keep private. Luckily, the ever-useful program CCleaner provides a method to permanently remove any deleted data from your hard drive.