What’s the primary cause of slow and unstable PC performance? It’s disk fragmentation.To be a Windows user, the need to defragment your hard disk is a simple fact of life.

As advanced as hard disk have become, one thing they are still not very good at is drive keeping. Every hard drive begins its life as a series of well-organized, neatly arranged and sequential files. When files are created, deleted, or modified it’s almost a certainty they will become fragmented. This means the file is not stored in one place in its entirety, or what computer folks like to call a contiguous location. Different parts of the file are scattered across the hard disk in noncontiguous pieces. The more fragmented files there are on a drive, the more performance and reliability suffer as the drive heads have to search for all the pieces in different locations.

Thus you need to do defragment your hard disk or you face a downward spiral of decreasing performance, slower access times for all your software and even worse performance for Windows itself. The Disk Defragmenter and Optimizer Utility is designed to reorganize noncontiguous files into contiguous files and optimize their placement on the hard drive for increased reliability and performance.

There are so many defragmentation software available today that it’s hard to choose one just fit with you. And few users know  that defragmentation tools can be found in freeware state and they perform quite good. we have selected 4 Best Free Disk Defragmenter And Optimizer for you to choose from.

Tip: The standard disk defragmenter in our operating system has only basic functions and the speed of it is very slow.

1, IObit Smart Defrag

IObit Smart Defrag

IObit SmartDefrag is an automatic disk defragmenter from iobit.com that keeps your hard drive space from becoming overly defragemented, totally free and 100% safe and clean with no adware, spyware, or viruses.Like virtually any defragmenting software it’s far superior to the built in Windows Defrag, but more than that I’d say it’s probably better than many of the commercial defragmenters currently on the market.

I’ve been using it for the last 3 releases,  and it indeed does a good job.  See more about IObit Smart Defrag.

2, Auslogics Disk Defrag

Auslogics Disk Defrag
Auslogics Disk Defrag is another one stand out in the crowded field of defraggers. It doesn’t only defragment files – it can also speed up your computer by optimizing file system. The makers say that their program was designed specifically for Windows7/2008/Vista/2003/XP and “for fast optimization of today’s modern hard disks.”

The user interface of Auslogics Disk Defrag is not a hassle even for the beginner and the wizard like process will make it extremely easy for you
to handle the application.

[Download & learn more about Auslogics Disk Defrag]

3, Defraggler

Defraggler is a file and folder defragmenter that enables us to defragment selected drives, and/or only selected files and folders. After initial analysis, it displays a list of file fragments, as well as their location on the disk map and allows us to choose the file to include in the defragmentation process. Defraggler differs from other defrag tools on the market, by enabling us to quickly and simply defrag the files we want to, without having to process the whole drive. Simply run it, select the file and defragment in seconds. No more struggling with the Windows defragmentation tool!

[Download & learn more about Defraggler]

4, MyDefrag

MyDefrag is a disk defragmenter and optimizer (a maintenance utility to make your harddisk faster) for Windows 2000, 2003, XP, Vista, 2008, Win7, and for X64. It is freeware, no time limit, fully functional, no advertisements. Fast, low overhead, with many optimization strategies, can handle floppies, USB disks, memory sticks, and anything else that looks like a disk to Windows. Included are a set of easy to use scripts for endusers, a scripting engine for demanding users, a screensaver, and a combined Windows plus commandline version that can be scheduled by the Windows task scheduler or for use from administrator scripts.

MyDefrag uses the Windows defragmentation API, so your files are at minimal risk. As with any powerful utility, you can shoot yourself in the foot – but there’s no “Delete File” command and thus no chance of destroying data due to a scripting error. At worst, you will shuffle files to the least optimal places they can be, causing disk access to slow down.

[ Download & learn more about MyDefrag ]

My favorite has always been IObit Smart Defrag but either one would meet your wishes.