How to Fix Disk Defragmentation Not Working Errors in Windows 11: Step-by-Step Solutions

Disk defragmentation helps improve your computer’s performance by organizing fragmented data on your hard drive. When defragmentation stops working in Windows 11, it can slow down your system and limit efficiency. Fortunately, there are simple ways to troubleshoot and fix this issue.

This guide will walk you through easy, step-by-step solutions to get disk defragmentation running smoothly again. Each step is explained in a clear and basic way, so even beginners can follow along.

By fixing defragmentation errors, you help your PC run faster and keep your files organized. Let’s start with some important quick checks before diving into detailed fixes.

Read on to learn how to resolve disk defragmentation not working errors in Windows 11.

Quick Note: Prerequisites and Initial Checks

Check your drive type: Disk defragmentation is mainly useful for traditional Hard Disk Drives (HDD). If you have a Solid State Drive (SSD), defragmentation is not necessary and Windows usually disables it automatically.
Ensure your PC is not in use: Defragmentation requires system resources. Close all programs and avoid using your computer during the process.
Verify your drive’s health: A failing hard drive can cause defragmentation errors. Run a disk check to make sure your drive is working properly.
Run Windows Update: Sometimes, bugs affecting system tools like defragmentation are fixed in updates.

Step 1: Run Disk Defragmenter as Administrator

Running the defragmentation tool with administrator rights can resolve permission-related problems.

Click on the Start menu, type Defragment and Optimize Drives, and right-click the app.
Select Run as administrator.
Choose the drive you want to optimize and click Optimize.

This ensures the tool has full system access to perform defragmentation properly.

Step 2: Check and Repair Disk Errors

Disk errors can prevent defragmentation from working. Running a scan and repair can fix these issues.

Open File Explorer and right-click the drive you want to defragment (usually C:).
Select Properties, then go to the Tools tab.
Under Error checking, click Check.
If errors are found, follow the prompts to repair the drive. You might need to restart your PC.

Fixing errors ensures the drive is stable enough for defragmentation to work effectively.

Step 3: Disable Scheduled Defragmentation and Enable It Again

Sometimes, the automatic defragmentation schedule can cause conflicts. Turning it off and back on can reset the process.

Open Defragment and Optimize Drives from the Start menu.
Click Change settings under Scheduled optimization.
Uncheck Run on a schedule (recommended) and click OK.
Restart your computer.
Return to the same settings and re-enable the schedule by checking the box again.

This step refreshes the defragmentation schedule and can clear any glitches blocking the process.

Step 4: Restart the Windows Defragmentation Service

The defragmentation tool depends on a Windows service called Optimize Drives. Restarting it can fix service-related issues.

Press Win + R to open the Run dialog.
Type services.msc and press Enter.
Scroll down and find Optimize drives or Defrag service.
Right-click it and select Restart.
If the service is not running, select Start.

Restarting this service can fix internal problems that prevent defragmentation from starting.

Step 5: Use Command Prompt to Defragment

If the graphical tool is not working, you can try defragmenting through the Command Prompt.

Open the Start menu, type cmd, right-click Command Prompt, and choose Run as administrator.
Type the following command and press Enter:

defrag C: /O

This command runs the optimization on the C: drive. Replace C: with your drive letter if needed.

Using the command line can bypass some interface issues and provide detailed feedback.

Step 6: Check for Third-Party Software Conflicts

Some antivirus or disk management software may interfere with Windows defragmentation.

Temporarily disable your antivirus or security software.
Try running the defragmentation again.
If it works, check the software settings to exclude defragmentation processes or consider switching to another program.

Conflicts can block disk optimization tools, so ensuring compatibility is important.

Alternative Method: Use Third-Party Defragmentation Tools

If Windows defragmentation still does not work, you can try reliable third-party defragmentation software such as Defraggler or Auslogics Disk Defrag. These tools offer more advanced options and sometimes fix issues automatically.

Make sure to download software only from trusted sources to avoid malware risks.

Frequently Asked Questions (FAQs)

Can I defragment an SSD?

No, defragmentation is not recommended for SSDs because it can reduce their lifespan. Windows 11 automatically disables defragmentation on SSDs and instead performs a process called TRIM to optimize them.

Why does defragmentation take so long?

The time depends on your drive size, fragmentation level, and system speed. Large or heavily fragmented drives take more time. Running defragmentation regularly can keep times shorter.

What if the defragmentation tool says the drive is already optimized?

This means the drive is either an SSD or has very little fragmentation. No action is needed in this case.

Can defragmentation cause data loss?

Defragmentation is generally safe and does not cause data loss. However, it’s always a good idea to back up important files before performing disk maintenance.

How often should I defragment my HDD?

Once a month is usually sufficient for regular users. If you frequently add and remove large files, you may want to do it more often.

When Nothing Works

If none of the above solutions fix the defragmentation error, you may be facing deeper system or hardware problems. Consider these final options:

Run the System File Checker: Open Command Prompt as administrator and type sfc /scannow to repair corrupted Windows files.
Check disk health: Use tools like CrystalDiskInfo to assess your hard drive’s condition.
Contact Microsoft Support: Visit the official Windows Support page for expert help.
Consider reinstalling Windows: As a last resort, reinstalling Windows can fix system errors causing defragmentation to fail.

Conclusion

Disk defragmentation not working in Windows 11 can slow down your PC, but it’s usually easy to fix. Start by running the tool as an administrator and checking your disk for errors. Refreshing the defragmentation schedule and restarting related services often solves the problem. If needed, use command-line options or third-party software for more control.

Always remember to check if your drive is an SSD, as defragmentation is not necessary for these. When problems persist, running system scans and seeking official support can help you restore your PC’s performance.

Following these simple steps will keep your hard drive healthy and your Windows 11 system running smoothly.