UltraDefrag is another powerful software that is available under the Open Source Initiative. UltraDefrag is a defragmentation tool written using C language for Windows NT. It is very fast, because the defragmenting is done by kernel-mode driver. For your information, defragmentation is a process that reduces the amount of fragmentation in file systems. It does this by physically reorganizing the contents of the disk to store the pieces of each file close together and contiguously.

UltraDefrag is the perfect replacement for the defragmentation utility for the built in one that comes with Windows XP as it is a much smaller size program and it runs much faster. There are three interfaces for UltraDefrag -graphical, console and native. It is a small and powerful program that can be used on Windows NT 4.0, Windows 2000, Windows XP, Windows Server 2003,Windows Vista and all of the 64-bit editions of Windows. If you are keen to know more, UltraDefrag has the following features:

• Very fast defragmentation, the work is done via a kernel mode driver which has an optimal defraging algorithm.
• Very small engine written in pure C.
• Nice graphical interface – compact and functional.
• Safety, because the file moving is accomplished with Microsoft’s own Defrag API.
• Simple to use.
• Ability to generate html reports of fragmentation status.
• Ability to include/exclude files based on simple filters.
• Native x64 support.
• Free: Distributed with full source code under the GNU General Public License.

You can download UltraDefrag from here.