Defraggler

Defraggler is a freemium defragmentation utility developed by Piriform Software, which can defragment individual files or groups of files on computer memory systems. Defraggler runs on Microsoft Windows; it has support for all versions since Windows XP. It includes support for both IA-32 and x64 versions of these operating systems.

Overview
Defraggler can defragment individual files, groups of files (in a folder) or an entire disk partition, either by the user's command or automatically on a schedule. It supports FAT32, NTFS, and exFAT. It can also be installed as a portable application on a USB flash drive. Defragmentation of RAID disks is also supported, although no details are supplied.

Defraggler was given a 5/5 star rating from Softpedia. In Lifehacker's Hive Five for Best Disk Defragmenter, Defraggler received first place.