Fix MMC Cannot Open the File C:\WINDOWS\system32\dfrg.msc Problem

One of my client’s computer encountered a problem which is unable to run Windows Disk Defragmenter. Windows Disk Defragmenter is a computer program included in Microsoft Windows designed to increase access speed (and sometimes increase the amount of usable space) by rearranging files stored on a disk to occupy contiguous storage locations, or defragmenting. The purpose is to optimize the time it takes to read and write files to/from the disk by minimizing head travel time and maximizing the transfer rate.

The problem is whenever he tries to run the Disk Defragmenter shortcut from Start > Programs > Accessories > System Tools > Disk Defragmenter, only an error window appears:

MMC cannot open the file C:\Windows\system32\dfrg.msc. This may be because the file does not exist, is not an MMC console, or was created by a later version of MMC. This may also be because you do not have sufficient access rights to the file.

MMC cannot open the file C:\Windows\system32\dfrg.msc

Here are some suggestions on how to fix running disk defragmenter problem in Windows.

One of the methods below should be able to help you restore Windows Disk Defragmenter. Try the first solution and then run Disk Defragmenter. If it didn’t fix the problem, continue with the second one and etc.

Solution 1: Make sure you have rights to run Microsoft Management Console (MMC) and MSC file.

Solution 2: Go to Start > Run, type regsvr32 msxml3.dll and click OK.

This may also be because you do not have sufficient access rights to the file

Solution 3: Go to Start > Run, type regsvr32 dfrgsnap.dll and click OK. Then again go to Run, type regsvr32 dfrgui.dll and click OK.

Solution 4: Go to C:\Windows\Inf, right click at dfrg.inf file and select Install.

Install DFRG.INF

Solution 5: Go to Start > Run and type sfc /scannow. Make sure you have your Windows XP installation disc in the CD/DVD drive.

Solution 6: Download and apply .MSC association fix.

Solution 7: Download and apply Defrag SnapIn registry fix.

Solution 8: Download and install latest MMC 3.0 from Microsoft.

One of the methods above should be able to help you restore your disk defragmenter. But for my case, I’ve gone though all methods above and it still doesn’t restore Windows Disk Defragmenter. Every time I run defrag, I still get the error MMC Cannot Open the File C:\WINDOWS\system32\dfrg.msc. After days of trying, finally I just decided to rename the dfrg.msc file at C:\WINDOWS\system32\ to dfrg-renamed.msc. I ran dfrg-renamed.msc, and I was shocked to see that it was able to run! So I created a shortcut for dfrg-renamed.msc and place it at Start menu and desktop for my client.

Until today I still couldn’t figure out what is causing this weird behavior but this workaround allows me to run Disk Defragmenter without getting the MMC Cannot Open the File C:\WINDOWS\system32\dfrg.msc error. I’d appreciate if you can share with me what might be the cause of this problem and how to really fix it.

46 Comments - Write a Comment

  1. Dark Phantom 8 years ago
  2. Dark Phantom 8 years ago
  3. Antonio 9 years ago
  4. Tony 10 years ago
  5. Prakash Choubey 10 years ago
  6. David B 10 years ago
  7. oseng72 11 years ago
  8. priyesh 11 years ago
  9. madi 11 years ago
  10. Shar 11 years ago
  11. zd 12 years ago
  12. Normando 12 years ago
  13. Hristian Kochev 12 years ago
  14. Cubina 13 years ago
  15. al 13 years ago
  16. david 13 years ago
  17. Anna 13 years ago
  18. supersyd 13 years ago
  19. Bearcat 13 years ago
  20. karan 14 years ago
  21. Robert 14 years ago
  22. Bill 14 years ago
  23. Alvaro 14 years ago
  24. khamim 14 years ago
  25. vyr 14 years ago
  26. Nhel 14 years ago
  27. Lefty 14 years ago
  28. Ariel 15 years ago
  29. Niki 15 years ago
  30. Georgi 15 years ago
  31. Art 15 years ago
  32. Lame Duck 15 years ago
  33. Mandi 15 years ago
  34. Acid_Boy 15 years ago
  35. ken 15 years ago
  36. Ladybug1440 15 years ago
  37. Stoyan 16 years ago
  38. sujahat 16 years ago
  39. ricky 16 years ago
  40. Sean 16 years ago
  41. William Brown 16 years ago
  42. philip 16 years ago
  43. Glenda 16 years ago
  44. John 16 years ago
  45. Stewart 16 years ago
  46. miden 16 years ago

Leave a Reply

Your email address will not be published. Required fields are marked *

Note: Your comment is subject to approval. Read our Terms of Use. If you are seeking additional information on this article, please contact us directly.