Fastest way for finding duplicate files on your computer

In this article we will discuss how to delete files fromother files in its directory.  You can also select: Send
your computer.to MS-Explorer.  Sometimes just seeing what these
If you are like me, you have made many backups ofother files are will give you confidence that it is safe
your music files, videos, and other files.  After ato delete a file.
while they start taking over your computer.  ButDirectory Report never automatically deletes files. 
you don’t know where all these backups are andYou must select which files to delete.  This is the
you may have even have forgot where they are.safest action.  Directory Report gives you the
Directory has many methods of finding your duplicatechoice of deleting a file permanently, deleting to the
files.  The quickest way of finding your largestrecycle-bin (safer), copying the file, moving the file, or
duplicate files is to perform a search based on filesreplacing the duplicates with a hard link. 
with the same size.  The resultant duplicate file list isA file is composed of two parts, 1 – the
shown with the largest files on the top.  Select anydirectory entry and 2 – the contents.  The
two files and do a binary compare.  This will showdirectory entry has the file’s properties (dates,
you if the two files are identical.  Although this is aread-only, owner and a pointer to the actual
tedious manual method you would be surprised oncontents).  If you have two files A and B, and you
what the largest duplicate files are and how easy it isreplace B with a link of A, then the duplicate
to free up huge amount of disk space.contents of B are deleted.  But both A and B point
The most accurate method of finding duplicate files isto the same contents.  Any change you make to A
to compare them byte by byte.  Unfortunately thiswill also make the change to B.
is also the slowest.  Directory Report has beenSelecting which files to delete manually can be very
revised 33 times and employs many tricks to speedtedious.  Directory Report has the capability of
up this process. selecting files in each duplicate group.  You can
The second most accurate method of findingselect the newest created files, select the oldest
duplicate files is to compare their Cyclic Redundancycreated file, select files that are in a certain directory.
Checksum (CRC).  This method is much faster thanDirectory Report has many filters so that you will
comparing byte by byte.  Directory Report uses theonly scan files you want.  This is much faster than
CRC-32 algorithm.  It takes each byte of a file andscanning every file on your computer.  You can use
passes it through the CRC-32 formula.  The result isfile name filters (Example: *.jpg), file name exclude
a unique 32 bit number.  If two files have the samefilters (Example: skip *.bmp),  Directory Exclude
size and have the same CRC, then they arefilters (Example: skip over the c:windows directory), 
identical.  Since Directory Report uses a 32 bit CRC,Size Date and other Filters (Example: only scan files
the odds of two different files having the same CRCwhich are more than 1 meg),  File Owner filters
is 1 / (2 ** 32).  This is number is extremely small(Example: only scan files owned by Allan), File Owner
– 2.3283E-10.  CRC-32 is used by Win-Zip andexclude filters (Example: do not scan files owned by
Win-RaR to ensure that unzipped files are identical toJared).
their source.Directory Report can save the duplicate file list to a
If you are not sure that two pictures or two videosprinter, text file, Excel file (CSV), XML file,
are duplicates, just double click on them.  DirectoryHTML file, clipboard, or directly to an Excel program. 
Report will launch the corresponding programDirectory Report has many settings.  You can save
associated with the files extension.them to a file and automatically reload them later. 
If you are not sure if it safe to delete a file, thenThis will save you a lot of typing when you run
select it, right click and select: Display in mainDirectory Report multiple times.
window.  This will show the file along with all the