Having just run Defraggler v2.21.993 (64 bit) version on a 320 Gb C drive on my Windows 10 Home laptop the 'Used Space' had increased by over 20 Gb at the end of the defrag. Surely the used space shouldn't have increased by that much over 20Gb as a defrag program should basically reorder the used locations of the sectors retaining to files?
A similar recent topic here about it:
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