Automated drive cleaning software tools are almost always one of three dominant kinds. The most common of these are the cleanup software products like Microsoft's Disk Cleanup utility, that are used to get rid of non-critical files and restore free space to the available pool. Another class is the Privacy Cleaner style utilities that remove signs of internet browsing and typed URL entries from the most common browsers such as evidence removal cleaners. Then there is the porn cleaner product, that is able to detect the existence of porn or offensive adult material and can manage the cleanup of these items. Yet another category of drive cleaning tools is the 'disk washer' style product, which can overwrite with 1s and 0s, random data from any part of the hard drive, so that it may not be used for malicious purposes.