I use either sysinternals contig, or the defragmenter that comes with Windows. I see no need for any paid software.
And I do it a few time a year on my main PC. Others do it less often, and that's good also. Some do it more often, because they think it's necessary or speeds up the machine. I doubt that.
Kees
What program do you use to defragment your hard drive? Which one of these programs I should use - Smart Defrag, Auslogics Disk Defrag, or Defraggler? And how often should I defrag?
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic