Disk Defragmenter

Currently I recommend 'Auslogics Disk Defrag' to home users and businesses alike. Disk Defrag performs the same job as the standard Windows program however I believe it to be a more effective tool for the job. There is a solid argument to suggest that manually defragmenting your hard drive is unnecessary with Windows Vista and Windows 7 and so it is only recommended to those people running XP, or who have Vista/7 and like a greater level of control over defragmenting their hard drives and system maintenance in general.

Disk Defrag is free software.

You can find it here:
http://www.auslogics.com/en/software/disk-defrag/download