Defragging impacts unrelated files?

[Ancient Brit]

I just experienced something slightly odd: I attempted to defrag a large file (a .zip consisting of several hundred fragments and roughly 8G in total size) and the result was a message indicating that complete defragmentation hadn't been possible (the file was brought down to 7 fragments, which is an improvement, obviously). Free space at the time was 19G (but not contiguous - I have no info on the largest contiguous free space fragment size).

 

So I re-analyzed the drive and suddenly found that more than half a dozen unrelated files suddenly appeared at the top of the list with 1000-2000 fragments apiece.

 

They included Program Files such as excelcnv.exe, which wasn't running at the time, and which shows a last accessed date that's over three weeks ago, which doesn't quite make sense to me - unless Defraggler is allowed to move other files around in order to accommodate its efforts, and thus risks increasing the level of fragmentation.

 

Unfortunately I didn't have /debug running or I'd be able to post data for analysis - sorry.

 

I've modified the shortcut so that /debug is invoked every time now, and if I can reproduce a similar effect I'll post info.

 

Any ideas as to whether this is expected behavior?

 

Best,

 

Peter