What If a Disk Won’t Defrag on Windows 7, 8, 10, 11?

If your disk won’t defrag on Windows 7, 8, 10, 11, this post is reliable enough for you to refer to. Several practical solutions to the very issue will be given to help fix this disk defragmenter not working issue.


By Michael / Updated on May 12, 2023

Share this: instagram reddit

Help, disk won’t defrag!

“Recently, I want to defragment my C drive, namely the system drive, because I found the transfer speed was a bit slow and the HDD was 47% fragmented. However, after running the optimization option several times, it still said 47% fragmented. How come? Could anyone else give a solution?”

The issue that disk won’t defrag

Generally, defragmentation is the way to reorganize files scattered around different clusters on a hard drive, putting them together and making them adjacent to each other. Thus, read and write speed can be improved and your computer can run faster.

Windows 7, 8, 10, and 11 have their own built-in defragmenter. It’s the most common tool when people wish to defrag any HDD. However, here is the thing – sometimes the defragmenter somehow doesn’t work and they can’t find any practical solutions.

Common problems of disk defragmenter Windows 7 not working

1. Disk Defragmenter service missing on Windows.

2. Windows defrag optimization not available.

3. Windows Disk Defragmenter not working.

4. Defrag won’t run in Safe Mode.

5. Defrag won’t launch, work, or open.

How to solve disk won’t defrag on Windows 7, 8, 10

It’s necessary to defrag an HDD when its fragmentation exceed 15% and it’s really a headache when Disk Defragmenter on Windows 7 does not work. But luckily, although it’s a complicated problem, there’re still many workarounds which may help you out. In the following contents, I picked up the top 4 of them.

Solution 1. Check the Disk Defragmenter Service

First of all, you’re supposed to make sure whether the Disk Defragmenter service is set up properly. If the service is not activated, then, you can’t run the defragmentation. Now, let’s see how to do the service check.

1. Hit “Win+R” simultaneously to launch the Run dialogue box and then, input services.msc and hit “ENETER”.


2. Ensure the Disk Defragmenter service is set to “Manual”.

3. Then, make sure the following services are set to “Automatic”.


Remote Procedure Call (RPC)

DCOM Server Process Launcher

RPC Endpoint Mapper

Now, it’s time to check whether Disk Defragmenter works normally and if not, proceed to Solution 2.

Solution 2. Stop any background program or app

end task

If you’re running any background programs for example, anti-virus program, Disk Defragment might be interfered with. So, you’d better disable those running apps and programs in the background.

1. Hit “CTRL+ALT+DEL” at the same time to bring up Task Manager.

2. Under the “Process” tab, right-click on the programs and apps you want to disable, then, select “End task”.

Solution 3. Use Disk Defragmenter in Safe Mode

If the issue of Disc Defragmenter Windows 7 not working still exists after trying the 2 methods above, then, you might as well try defragging your HDD in Safe Mode. This mode enables users to run with only default settings and drivers, which minimizes the software conflicts and helps fix the problematic defragmentation.

Solution 4. Try third-party freeware utility

If none of the above ways work, maybe a third-party software utility for disk defragmentation is your last choice. There’s too much software in the market claiming to defrag HDD and if you have no idea which one to choose, here, I recommend AOMEI Partition Assistant Standard, a free powerful disk manager utility, able to analyze and defrag a disk in only a few clicks. More than the disk defragging feature, you can also use it to format disk and wipe a hard drive.

Disk won’t defrag on Windows 10, 8, 7? Try another better alternative to make everything easier!

Download Freeware Win 11/10/8.1/8/7/XP
Secure Download

Step 1. Install and run AOMEI Partition Assistant Standard. After that, right-click on the target disk and select “Disk Defrag” or just hit “Disk Defrag” in the popped menu. 

disk defrag

Step 2. Tick the target disk and hit “Analyze”.


Step 3. It’ll take a few minutes before completed. Then, the disk will be scored based on its fragmentation rate.


Step 4. Start the defragmentation by clicking on the “Defrag” button.


Step 5. Wait a few minutes again before it’s done. Then, the defragged disk will be scored again.


Optional: How to speed up an SSD efficiently?

partition alignment

Over time, an HDD can be slowed down as well as an SSD. However, due to their different working principles, the ways to enhance the 2 types of hard disks are different. As for HDD, you can make it run faster by defragging it; however, in SSD, it’s another story. If you defrag an SSD, unnecessary tear and wear will be caused which in return shortens its lifespan. Luckily, by upgrading AOMEI Partition Assistant Standard to its Pro edition, you can enjoy the feature of SSD 4K alignment to boost up the hard disk and get the most out of it!

Note: By using the professional edition, you can make the defrag run daily, weekly, monthly, or run on a certain condition such as at startup or logon because this edition allows for schedule defrag.


What if a disk won’t defrag? To help you out, 4 practical solutions are introduced. As for me, AOMEI Partition Assistant in Solution 4 really worked out. I love it so much for its convenience, user-friendly interface, and feature-rich nature. Plus, if you want to use this software on Servers, please try the Server edition.

Michael · Staff Editor
Michael is a professinal editor of AOMEI editor team.