Windows 7 Disk Defragmenter Does not Work

I am suddenly getting the following error message when trying to run Defrag

'Disk Defragmenter cannot start because the task scheduler service is not running. Start the task scheduler service and try again.',

which does not work.

Assuming the task scheduler was enabled and the defragmenter still does not work, here is a routine I compiled over time that has proven effective in resolving defragmenter issues:

There are several reasons why the built-in defragger may not work properly:

0. There is malware on the system. Solution: Run an Anti-Virus check and also a Spyware check.

1. The disk is too full (you need at least 15% free space, sometimes 20%). Solution: Delete unneeded files and programs till you have more than 20% free space.

2. The disk is damaged and needs to be repaired. Solution:  

a. Open "My Computer" and right click on the drive you want to de-frag.  
b. Select "Properties" and click on the "Tools" tab.  
c. Select "Check now" to check the disk for errors.  
d. Select both options and click "start";

(It may take a while and the PC may re-start so it can do the check at boot time. Be patient and let it complete).

3. Disk Defragmenter may be corrupted, needing a System Restore to correct it. Solution:  

a. Start - All Programs - Accessories - System Tools - System Restore (click to open);
b. Select a restore point well before you started having problems with Disk Defragmenter;
c. Start the restore process and let it complete (Name the restore operation something descriptive like "Defrag Repair").

4. There are other programs running that interrupt the built-in defragmenter. Solution:
a. Close all running programs.
b. If you suspect there may be some programs running in the background,
c. Press Ctrl+Alt+Delete and
d. Select "Start Task Manager"
e. Under the "Applications" tab you will find a list of all running applications -- you can close these by selecting "End Task."

5. If still no luck, try disabling the screen saver when running Disk Defrag (you should pretty much leave the system alone when running the built-in defrag utility).

6. If still no go, try running the defragmenter in Safe Mode. If it runs, something is interfering with it and tracking the interference down may not be easy. Note: Some versions of Win 7 disable the ability to run the built in defragger in safe mode. If disabled, it will say so when trying to run it in safe mode.

7. Disk Defragmenter may no longer be on the system or is so corrupted that it needs a re-install. Solution: Re-install the built-in.

There are several methods to re-install the built-in defragger:

a. Open the "Start" menu.
b. Type "%Windir%\Inf" in the "Search" box and press "Enter".
c. In the window that opens, find the file named "dfrg.inf".
d. Right-click on "dfrg.inf" and "Install."

a. Go to "Start > Run" on your computer.
b. Type "rundll32.exe setupapi,InstallHinfSection DefaultInstall 132 %windir%\inf\dfrg.inf" and press "Enter"
3. Click "OK" to make the program automatically reinstall itself.

a. Go to Start >All Programs>Accessories>Right Click on Command Prompt> select "Run As Administrator"
b. At command prompt, type "regsvr32 dfrgsnap.dll" and hit "Enter."
c. Type "regsvr32 dfrgui.dll" and hit "Enter." This will reinstall any missing defragger files.

8. Most problems will resolve by #6 above, but if not and if your windows install is otherwise running fine, you should consider downloading a free trial of a commercial defrag tool as opposed to doing drastic actions to restore the built-in's functionality. Third party programs  are more robust and many work in the background so you can use your PC while defragging.

Most third party programs offer a free, fully-functional trial (the better ones are for 30 days). Installing one of these will disable the built-in and if you decide to uninstall it, removal will replace the built-in, many times repairing it in the process -- it's worth a try. . ..

Here is a recent Top 10 Reviews side-by-side comparison of the best defrag programs available:

The top placer is the only defrag program that also prevents fragmentation (see the review).  

Why is it good to prevent fragmentation?

Basically, it drastically increases your hard drive's life expectancy (especially since you don't have to leave the system on all night -- a much "greener" practice), not to mention it will also increase system performance.

Check out what the review has to say on this.

Good luck to you!

Bill R TechSpec

PS: If still no go, repair may involve registry editing or repairing the windows installation and possibly re-installing windows itself. These are not simple solutions. If needed, state so and they can be provided.

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Question Info

Last updated June 20, 2020 Views 20,973 Applies to: