Options (Find Duplicate Files)

 
This option limits the file types that the program considers when searching for duplicates. For example, to search for duplicate audio files only, choose the Audio file type.

The choices are:

•All File Types

•Application

•Audio

•Document

•Image

•Text

•Video
 

Note:
The program uses a file's extension to determine the file type.  The extension must be in the System Registry (in HKEY_CLASSES_ROOT\SystemFileAssociations) and have its PerceivedType value set to the corresponding value (application, audio, document, image, text, video).  For example, here's a screenshot of the System Registry showing that the PerceivedType of a XML file is "document".

The software program that creates the files having a particular extension is ordinarily the one that registers the perceived type for the extension. Changing these settings might impact your system.
 

 
These options define what it means for two files to be duplicates of each other.  You may consider two files to be duplicates if they have the same name.  Another person whose needs differ from yours may consider two files to be the same if they have the same content, regardless of their names.  It really depends on the situation and what you are using this tool for.  Choose any combination of the following options:

•Names Match

•Sizes Match

•Last Modified Date/Times Match

•Contents Match

File timestamps can be a little unreliable to use as duplicate criteria due to how the different versions of Windows handle timestamps.  Two files can be identical yet have differing dates.  Don't put too much stock in differing timestamps. 

The program requires you to select either the Names Match or the Sizes Match criteria as an initial selection.  You can then add any of the other criteria.
 

 
You should not remove some files on your computer, even if they appear to be duplicates. These include System files, Hidden files, and files in the Windows folder hierarchy.  Removing any of these files can cause your system to become unstable or unusable.  FolderMatch's default behavior is to ignore these types of files when searching for duplicates.  You can override the program’s default behavior by deselecting these three options:

•Ignore System Files

•Ignore Hidden Files

•Ignore Files in Windows Folder Tree

Additional Ignore options include:

•Ignore Temporary Files

•Ignore Zero Byte Files

A Temporary file (or temp file) is a file created by a program to hold information temporarily. After the program is closed, it should delete the temporary file. But sometimes this does not happen. Microsoft Windows and Windows programs often create a TMP file as a temporary file. If a temp file is in use, you don't want to remove it.  If it's old and should have been removed but wasn't, it should be safe to remove it.

Zero Byte files are files whose size is zero bytes; they contain no contents.  These files do not concern most users since they are not taking up any hard disk space.  

FolderMatch automatically ignores two other groups of files: files in the Recycle Bin and files in the FM_DUPES folder.  You cannot change this behavior.
 

Press one of these buttons to bring up a window where you can enter files and folders to include or exclude from the search. For files, you may enter a complete file name, like "thumbs.db" or you may enter a File Pattern using the wildcard characters * ?  like "*.dll".  For folders, enter the entire folder path or select a folder by clicking on the three dots .

Enter a file name or folder path and press the Add button to add the item to the list.  To remove an item from a list, select the item and press the Remove button.  To remove all items from a list, click on the Clear List link.

For a discussion of file patterns see the help file topic on Include/Exclude Filters.  Only the portion of that topic which deals with file patterns is applicable to the find duplicate files feature though.
 

The program can remove duplicate files in several ways. It can move the files to another folder, delete the files permanently, or move them to the Windows Recycle Bin. These three options are the Removal Methods. The safest removal method is to move the file to another folder. This way, you can quickly restore it if needed. The program moves the files to a folder called FM_DUPES.

The FM_DUPES folder is a subfolder of the FolderMatch local application data folder. When the program moves a file to the FM_DUPES folder, it keeps the original path information as part of the moved file's new path. For example, if the file’s original specification was “C:\My Stuff\My Docs\Resume.doc”, the file’s new specification will be “C:\…\FM_DUPES\C\My Stuff\My Docs\Resume.doc”. The highlighted portion of the new file path shows the original path of the file.  This makes it clear to see where a file came from and allows you to restore the file easily.   Click on the Maintain FM_DUPES Folder button to go to the Maintain DUPES folder window to interact with the FM_DUPES folder and its contents. This window offers the easiest way to restore moved duplicate files.

The Move To Recycle Bin option is also relatively safe.  You can restore files removed in this way using the Recycle Bin’s built-in functionality.  You should note, however, that Windows does not move files on removable or network drives to the Recycle Bin; it deletes them permanently. So, if you remove duplicates from either of these drive types, using this removal method, know that you won’t be able to restore them. This behavior is per Microsoft Window’s design - FolderMatch has no control over this. 

The Delete Permanently option is very dangerous and is one you should rarely use.  You cannot restore files removed in this manner without the aid of an undelete utility. 
 

 
Check this box to have the program automatically mark duplicates at the completion of a duplicate file search. The program will use the current Mark for Removal rule. 

See the Mark Files window topic for more information about the rules.
 

Check this option to see the Search Results Summary window after a duplicate file search completes.

 
When performing a Contents Match search, the program must examine the contents of each file. Sometimes a quick scan of parts of each file can spot differences without having to scan the entire file. This might speed up the duplicate files search.
 
Check this box to have the program perform a quick, partial scan of a file before performing a scan of the entire file. Uncheck this box to have the program perform only a scan of the entire file.
 
Note that while this setting may speed up the search, it's also possible that this extra scan may slow down the search because of the additional scan (partial + full scan).  It will depend on the number of files, their sizes, how many are duplicates, etc...