Defraggler!

UltraDefrag is powerful and fast defragmentation tool for Windows. There are three interfaces to them: graphical, console and native. The GUI is useful, because it represents your filesystem visually as a color-coded cluster map. The console is another option for those that prefer the command line. It allows you to run UltraDefrag from the task scheduler and scripts. Finally, the native executable will run at boot time in a manner similar to chkdsk. The design of UltraDefrag is very simple. There are no skins and other unnecessary stuff. It is a small and powerful program! »

[Be careful during the installation: Forum ]

O&O Defrag packs file fragments quickly and securely back together to optimize your hard disk under Windows. You can now see what the program does for your system thanks to graphics and statistics, which give you a before-and-after Defrag contrast. Its functionality ranges from a fully automated defragmentation to an individual professional set up. It can do everything a truly good defragmentation software should be able to do.The new background monitoring function helps to prevent fragmentation at source. Newly added and modified files are analyzed and defragmented whenever they are not being accessed. O&O Defrag makes sure that your hard disk is constantly performing at its peak. »

PerfectDisk is a disk defragmenter with a variety of advanced disk management features. It supports automatic background defragmentation, flexible scheduling options, and boot-time defragmentation of locked system files. PerfectDisk's innovations, such as the patented SMARTPlacement optimization, free space consolidation with Space Restoration Technology, large drive support, and single-pass defrag, to name a few, continue to set the bar for the defrag market.

WinContig is an easy-to-use stand-alone defragmentation tool that doesn't create any installation directories or Registry entries on your computer. Its purpose is to quick defrag files without the need to defrag the whole disk. In addition, WinContig allows you to group files into profiles, and also it accepts a number of optional command-line switches that you can use to control how the program operates.

Disk Defragmenter is a computer program included in Microsoft Windows designed to increase access speed by rearranging files stored on a disk to occupy contiguous storage locations, a technique commonly known as defragmenting. The purpose is to optimize the time it takes to read and write files to/from the disk by minimizing head travel time and maximizing the transfer rate. Disk Defragmenter is also used to improve system startup times.

Puran Defrag is a very simple disk defragmenter which will defrag the files and optimize your system, collecting all the fragments of a file and putting them together, as well as moving some frequently used files and all directories to faster disk areas. This process boosts your hard disk performance and thus overall system speed. In addition it reduces wear and tear on your hard disk, thereby increasing its life span.

Diskeeper 16 is a unique approach to Defrag, the effort of arranging files on the physical disk/media to improve speed and performance.

Stellar Drive Defrag optimises and defrags OS X Mac Yosemite hard drives. Defrag support is extended to Mavericks, Mountain Lion, Lion and Snow Leopard. The software remove fragmentations from small and large files and enhance overall Mac performance. Stellar Drive Defrag for Mac consists of 4 powerful algorithms to defrag Macintosh HD. User can also optimize the free space available on the disk drive. Further, this tool monitors temperature of the hard drive and indicates if it goes beyond the limit. To defrag startup drive of Mac, user can create boot DVD with the help of Stellar Drive Defrag software. Different user licenses are available for Single and Multiple Mac OS X. »

Vopt-fast disk defragmentation.Vopt lets you quickly defrag and pack your disk drives to maintain optimal performance and reliability. Vopt's speed makes daily defragging both practical and desirable. Vopt also provides tools to assist you in maintaining your system, reclaiming wasted disk space, and protecting your privacy.

Over time, the operating system itself ends up scattered all over your disk.

DiskTuna is an easy to use, on-demand, no frills disk optimizer and defragmentation utility for FAT, FAT32 and NTFS formatted drives. Through a simple to use mechanism you can create ‘jobs’ that enable you to schedule or launch disk optimization with just one click. DiskTuna is freeware. DiskTuna reorganizes your disk and will make it faster and more responsive.