My personal favorite is DUPLICATE FILE FINDER, by Rashid Hoda
Current version is 1.0.2.8
http://srhoda.250free.com/DupSetup.exe
Note that this util also has the ability, as Thorkild points out, to do
byte-by-byte EXACT file comparisons, to be sure that say, two images
with totally different names, but the exact same filesize [say, jpeg's
of 203,267 bytes) are EXACT dupes.
You can, as the review below indicates, do analyses several different
ways.
What I esp like is the ability to customize it. Say, in one particular
run I ONLY want to compare files by same size in, say, FOLDER-001,
FOLDER-002, FOLDER-007. Then, I just select check by size [which
ignored filename, etc} and then select the various folders I want to
search.
Here's a review:
Free Duplicate File Finder Features:
Works on Windows 95, Windows 98 & 98 SE, Windows ME, Windows NT (any
version), Windows 2000, and Windows XP
Simple and small installation program with un-install option.
Easy to use graphical user interface.
No nag screens, delays or limitations of any kind.
No adware / spyware or other "hidden features".
Search any folder(s) or drive(s) combination(s) that you want to scan.
No limit on number of files, folders or drives.
Drag & drop folders or shortcuts that you want to scan.
Load & save different search profiles.
Last used search profile automatically saved on exit.
Last 9 search/saved profiles available in file menu for easy access.
Fast search algorithm with various search options.
Export duplicate file list information to various file formats.
Switchable match by file content (binary file compare).
Switchable match by file content and name (binary file compare + name
matching).
Switchable match by name and content.
Switchable match by file size only (no binary file comparison).
Selectable zero length file skipping.
Selectable minimum and maximum file size searching.
Switchable subdirectory scanning.
Switchable delete to Recycle Bin or directly delete from hard disk.
Open windows explorer in a matched file's directory to check the
contents of the folder/file.
Expandable file type search filters.
Multiple simultaneous file filters.
Image preview for graphic files (currently BMP, GIF, JPEG supported).
Mark and delete all duplicate files.
Display drive space that would be free from deleting marked files.
Statistics for duplicate files, disk space used by duplicate files and
number of duplicate files.
Statistics for amount of hard disk space that would be free by deleting
duplicates.
