Uninteresting Background details:
I had a problem with defraggler when I was fooling around with my "pagefile.sys". And maybe Windows-defrag was secretly running in the background. Defraggler took my HDD with 2% fragmented files and increased it to ~30% fragmented files. It was painful. I could see Defraggler splitting up my files, and I didn't want to use Microsoft's defrag to fix it - so I ran Defraggler 6 times before my files were somewhat defragmented. I could see how my free-space had become fragmented and I saw the problems it was causing for Defraggler (almost as if defraggler fails to remove data that is blocking the defragmenting of a fragmented file).
My suggestion:
Could you add an option that gives me manual control of the colored squares in Defragglers status-display? So if the freespace is a mess and I have lots of big files left, then I could just click & drag some of those light-blue blocks to another area of the HDD and eventually free enough white squares to drag one of the large fragmented files into it's place.
So when I click a block, Defraggler should read which file is there and select all fragments of that file. Then when I drag my mouse to a white spot and release, then Defraggler will put all the selected fragments in a neat (defragmented) row, right there!
I love manual control, it would really please me if I could just click & drag & drop my files to anywhere on my harddrive. Then I could drag all of the large files to the end of the drive and leave them there. Windows does not allow you to choose where on the harddrive you want to put stuff
It would also enable me to sort my freespace any way I want!
Possible problems:
each colored square may hide multiple files or fragments. This could be solved by either selecting them all and have Defraggler count the number of files represented and placing them in sorted order when the mouse is released on a white square. Or Defraggler could just select the top-most file and let you move it. But then you would have to click a lot of times when a square conceals numerous tiny files.