Review: MyDefrag 4.2.6

MyDefrag is ideal if you are looking for a defragmenter that is thorough, highly customizable and free.

You might be familiar with the defragmenter called JkDefrag. The name has been changed to MyDefrag beginning with version 4.0b1 in February 2009. MyDefrag is simple to use with powerful options.


Note: New releases are made available on an ongoing basis. Please check the MyDefrag download Web page for the latest release.

Who's it for?

MyDefrag is for those users and administrators looking for a better defragmenter than Windows Disk Defragmenter. MyDefrag is ideal if you are looking for a defragmenter that is thorough, highly customizable and free. However, if you are looking for a fast defragmenter, then MyDefrag probably isn't for you.

What problem does it solve?

MyDefrag does a better job defragmenting than Windows Defragmenter and performs optimization not available in Windows Defragmenter. Advanced users can create scripts that defragment exactly what they want how they want.

Standout features

  • Simple GUI with detailed explanations: The main screen is simple and provides descriptive text for each option.
  • Three levels of disk data management: MyDefrag not only defragments fragmented file segments but also consolidates and optimizes files so they are contiguous and in an optimal physical location on the disk.
  • Seven standard modes of operation: Built-in scripts provide seven run-time options:
    • Analyze only, Consolidate free space and Defragment only: You may not want to perform the standard defragmentation, consolidation, and optimization that occurs when the Optimize Monthly, Optimize Weekly or Optimize Daily options are chosen. The Analyze only, Consolidate free space and Defragment only options perform a subset of these tasks.
    • Flash memory disks: This option is specifically designed for flash drives and SSD drives. Moves as little data as possible while still providing the benefits of defragmentation and consolidation.
    • Optimize Daily: Fast defragmentation and optimization.
    • Optimize Weekly: Medium level of defragmentation and optimization.
    • Optimize Monthly: Thorough defragmentation and optimization.
  • Extremely detailed graphical interface: If you are used to seeing small squares that represent and show the defragmentation process you might be surprised with the detail shown in the MyDefrag GUI. A percentage complete status is also displayed for each step in the process.
  • 32 and 64 bit support: The standard setup file automatically detects the bit version of Windows and installs the appropriate 32 or 64 bit version.
  • Safe: Uses the Microsoft standard defragmentation API.
  • Single or multiple drives select: Unlike its predecessor, MyDefrag allows you to select one or more drives.
  • Multiple language support: Support for 22 languages.
  • Help File: MyDefrag comes with an excellent help file with information for both new users and power users.
  • Screen Saver mode: This is a nice feature that defrags your drives when Windows goes into the screen saver mode but there is a catch (see What's Wrong below).
  • Run from bootable CDROMs and flash drives: You can use MyDefrag from a bootable device to better defragment system files.
  • Boot-time defragmentation: You can schedule a MyDefrag script using the Windows Task Scheduler to run at boot-time.
  • Command Line support: You can run any of the included scripts from the command line. Example: "P:\Program Files\MyDefrag v4.2.6\Scripts\OptimizeWeekly.MyD" C:
  • Unique scripting language and customizable scripts: J.C. Kessels developed a scripting language designed specifically for MyDefrag. The standard scripts and sample scripts are included if chosen during setup and can be modified by the experienced user.
  • User customizable settings: You can change a number of settings to customize MyDefrag by modifying the \MyDefrag v4.2.6\Scripts\Settings.MyD file.
  • Freeware: MyDefrag is absolutely free for both business and personal use. You must agree to this simple EULA.

What's wrong?

  • Slow: The large amount of data that has to be moved to defragment, consolidate and optimize a Windows logical drive requires a lot of time to do right. There is just no shortcut for the level of data reorganization that MyDefrag performs. The developer claims that MyDefrag is faster than Windows Disk Defragmenter.
  • Confusing nomenclature: Options on the main screen are called scripts which might be confusing to the average user.
  • Confusing options: When you first launch MyDefrag it is confusing which option should be chosen first. You might want to choose the Analyze only option first to see which logical drives should be optimized. Or you might decide to jump right to the defragmentation. J.C Kessels recommends performing the Optimize Monthly option first since it is the most thorough. Then run the Optimize Daily option each day or schedule it to be run each day.
  • Scheduled task runs only when computer is on: If the Create a scheduled task for daily optimization, every day at 05:00 AM option is chosen during installation the task fails to run if the computer is off and the task start time is missed. To resolve this issue, find and open the MyDefrag v4.2.6 Daily task in the Vista or Windows 7 Task Scheduler, click the Settings tab and check the Run task as soon as possible after a scheduled start is missed check box and then click the OK button. Note:  If the computer is left on, the UAC will prompt you when the 05:00 AM task starts requiring your presence. A missed task will be queued at system start-up and, by default, will start after 10 minutes. When the task starts, you will be prompted by the UAC.
  • No 'run when idle only' option: MyDefrag runs when manually started or scheduled and will slow down your computer when running. There is a possible workaround. MyDefrag can be run at a lower priority with a change to the \MyDefrag v4.2.6\Scripts\Settings.MyD file.
  • Screen saver mode requires UAC to be turned off: The UAC must be turned off before installing MyDefrag for the screen saver option to work properly. The UAC is an important component of Windows Vista and Windows 7 security and turning it off is not recommended.

Competitive products


Licensed/Fee based

Bottom line

If you are looking for both thorough and free in a defragmenter then look no further than MyDefrag. However, you may not need or want the level of defragmentation and optimization that MyDefrag performs. If this is the case, then you might want to look at other faster defragmenters like Auslogics Disk Defrag.

User rating:

Have you encountered or used MyDefrag 4.2.6? If so, what do you think? Rate your experience and compare the results to what other TechRepublic members think. Give your own personal review in the TechRepublic Community Forums or let us know if you think we left anything out in our review.

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Alan Norton began using PCs in 1981, when they were called microcomputers. He has worked at companies like Hughes Aircraft and CSC, where he developed client/server-based applications. Alan is currently semi-retired and starting a new career as a wri...


Diskeeper in default mode hits the hard drives continously with little positve effect, possibly it might do well on servers, but I'm not happy with it. There's many forum posts on this, I consider it well documented.

Perfectdisk causes major slowdowns on directories with 20-50K files or more, especially if they're small files, it also causes slowdowns on writes, because of the optiwrite technology (which is otherwise clever, of course you could turn that off, but that would leave it no better than most freeware defragmenting solutions). Other than that, Perfectdisk does well even on almost completely full 4 TB drives.

Caveat: Don't use the Perfectdisk SSD optimize on an Intel 520 SSD firmware 400i on an ICH10R controller with Rapidstorage driver, it starts on 1% and after 4 hours, it's still on 1%. i.e. it doesn't work, except for putting wear on your SSD. Don't use it on a OCZ RevoDrive X2 either, it will only run for like 10 seconds (i.e. the drive's own super aggresive Garbage Collection has left it nothing to do).  

I don't know the current version of Speedisk, but last I played around with it, several years ago, it was a watered down version of Diskeeper. So kind of like Windows 7 defrag.

As far as I'm concerned, and for my use at least, MyDefrag beats both of them.

In fact the closest competitor may be Puran Defrag, which has an installer that will download an extra program to install, dealer's choice, keep your eyes peeled and you can abort that download, apart from that it's really good and much faster than MyDefrag, it's just not as good.

You may want to take a look at and draw your own conclusions.


"MyDefrag" is an excellent tool and I use it about once a month. I'm sure you have heard of "UltimateDefrag v 4" by "Disktrix" which is a very powerful tool which you can virtually set and move files where ever you want on your disc and do just about what ever you please. Just one question, I have used Ultimate Defrag just to try it out and it works completely different than MyDefrag moving files to different areas and then Wins7 just moves them back. Have you ever tried UltimateDefrag... ?


I installed it on my Toshiba laptop and run defrag but the screen resolution did not work, I tried changing it but could not get it to go, so I removed it. so I dont know if it works or not sorry about that. Cheers Harry


I tested MyDefrag and found that while it defragmented the drive fine, "previous versions" dissapeared and "system restore" checkpoints vanished. I'm moving on to something else.


Vs. a paid option such as Diskkeeper, MyDefrag does a great job - most typical users can run the day, week, month depending on how often they in fact run it, and it simply works. The point on Screensaver mode is well taken, esp. on Windows 7 and Vista machines - don't turn off UAC unless you know what you're doing!

Alan Norton
Alan Norton

I use MyDefrag and prefer it over Windows Defragmenter. You might want to check out the Photo Gallery. I detail the options available during the MyDefrag installation and you might find some of them confusing. As always, I will be participating in the forum whenever I can add something meaningful to the discussion

Mark W. Kaelin
Mark W. Kaelin

Have you tried MyDefrag lately? What did you think of it?

Alan Norton
Alan Norton

Thanks for the information. I will keep an eye open to see if I have the same problems on my system. 'Previous Versions' is important to me. Edit: I just ran the Optimize Monthly script for drive C: (Windows 7 Ultimate x64) and then drive D: (Docs) and then ran the same script for all drives. The three system Restore Points were still there. For the couple of files I checked, the Previous Versions remained intact. For one file all ten Previous Versions remained intact.


I've used MyDefrag (and its predecessor) for a couple of years. I have encountered no major issues and it works really well. The one change I always make is on installation I change the folder to MyDefrag and remove the version number from the folder name. Otherwise every time you update you need to not just uninstall the older version but also modify the task scheduler so that it points to the right folder for the scripts.

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