A quickie way to detect duplicate in the same directory (folder) is to sort by file size.
If you think you have duplicate files scattered about your hard drive, then you may want to consider one of the following:
NoClone finds duplicates by performing a byte-to-byte comparison of files. This program worked great for tracking down and deleting duplicate digital photos on my hard drive. You can also use this one to de-dupe files over a network. (Shareware/Windows)
Directory Report 19 quickly catalogs large drives and lets you sort by several different criteria to find which files you need and which are duplicates. This one is my favorite because you can also easily print directories for hands-on comparisons and export to Excel to view in a spreadsheet format. (Shareware/Windows)
FolderMatch lets you compare the contents of two folders on any drive, even CDs. Use this one to sync between hard drives, computers, or your laptop. It also offers a helpful wizard to guide you through the process.
I have somehow made extra copies of photos, and other items. How do I find them without knowing what I am looking for? I use WinXP sp2
Thanks for the help!