Comment by Microsoft MVP

John Barnett

NoClone

There are numerous applications on the market that purport to recover disk space. The only problem is they are not always as successful as they make out. The main culprit for bloating your and thus reduce your disk space is duplicate files. These files scatter themselves all over your hard drive gobbling up space at a rate of knots. In many instances these duplicate files are simply redundant and, therefore, not contributing anything to your system other than taking up valuable space. NoClone uses a byte by byte comparison to search for duplicate files such as picture, video, music, DLLs and a host of other files so that you can effectively and safely delete everything that is not needed. It even has a smart marker system to enable you to locate duplicate files by date, version, size, folder and file name pattern. 

Reference: http://xphelpandsupport.mvps.org/lifesavers.htm