In WinXP or Vista, you can easily sort by size using the "DOS" command:

DIR *.* /S /O:S

This won't necessarily show duplicates of the same file adjacent to each other, but will show all files of exactly the same size in a single clump.

The simple fact that the number of files has bloomed to "unthinkable" numbers, and the very common use of "common files" in multiple necessary places makes the kind of manual detection of duplicates done with XTREE results rather impractical. There are just too many files on "modern" machines to make more than superficial "cleaning" practical. You can certainly remove obvious large dupes, but finding all the redundancies is too time consuming to be worthwhile (and a bigger hard drive is so cheap).

As an example, I have more than 70 "duplicates" of one file that is necessary in each place where it appears, because one of the users whose stuff is in my backups downloaded .htm files of a bunch of manuals and instructions from Gateway. Each of these .htm files has an "associated folder" containing the graphics and other "style lumps" that Gateway uses on all their web pages, so this particular .gif (along with 17 or 18 others) is in the linked folder for each of the Gateway .htm files. Deleting any one of them makes the associated .htm file "unloadable."

Had he saved as .mht (web archive) files those same .gif etc files would have been embedded in each of the .mht files, but wouldn't show as a separate file in each place.

Some Vista versions have a fairly sophisticated "synchronize" function that lets you, for example, keep a matched set of files on your desktop and on your laptop. Theoretically, according to Microsoft, the "synch" utility has the ability to remove duplicate files, although the exact way in which it does this is not too clear. Mickey give lots of "assurances" that it's wonderful, but not much in the way of useful information about what it actually does.

I don't believe this function is present in either Vista Home Basic or Home Premium. You have to move up to Vista Business or Vista Ultimate to get it. For my purposes, I consider it too dangerous to attempt to use, based on Microsoft's sparse description of how it works; although I do have it available on my desktop machine.

John