Fix: Explorer.exe class not registered [Win 10, Edge, JPG]

Milan Stanojevic
by Milan Stanojevic
Deputy Editor
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  • Windows 10 is a great OS, nevertheless, it's safe to say that we all had our fair share of errors now and then.
  • The Explorer.exe class not registered error has a great potential of ruining the Win10 experience for you, but with a few easy tweaks from this article, you should be able to get it out of your way.
  • DLL files and EXE files alike can cause similar issues -  take a look at these Exe File Errors guides for more details.
  • Get a taste of peace of mind by bookmarking our Windows 10 Troubleshooting Hub to help you keep all errors at bay.
how to fix Class not registered error on Windows 10

We have all encountered an error on Windows 10, and speaking of errors, it seems that some users are having Class not registered error.

As far as we know, this error can affect almost any software, and users have reported that Google Chrome isn’t working on Windows 10 due to this error.

Google Chrome isn’t the only software affected by this issue, so let’s fix Class not registered error on Windows 10.

Class not registered error message can cause various problems on your PC, and speaking of issues, many users reported the following problems as well:

  • Class not registered error when opening pictures, videos – According to users, this error message can appear while trying to open pictures or videos. If you have this problem, be sure to try out some of our solutions.
  • Class not registered Windows 10 Photos – This error can appear on any version of Windows, and many users reported it while trying to run Photos app.
  • Class not registered explorer.exe, Excel, regsvr32, Taskbar, uTorrent, Internet Explorer, Outlook, Microsoft Edge, Windows Media Player – Many users reported this error message while trying to run various applications. According to them, this error message can appear in Outlook, Edge, Internet Explorer, but it can also appear while using Windows Explorer.
  • Class not registered PDF – In several cases, users reported this error while trying to open PDF files. This can be an issue, but you should be able to fix it using one of our solutions.
  • Class not registered msstdfmt.dll – DLL files can sometimes cause this issue, and if you experience it on your PC, be sure to remove the application associated with that DLL file and check if that solves the problem.

How to fix class not registered error in Windows 10

  1. Disable iCloud
  2. Re-register ExplorerFrame.dll file
  3. Use Component Services
  4. Create a new Microsoft account
  5. Check your hard drive

1. Disable iCloud

Some reports show that this issue is caused by iCloud, and in order to fix it, you need to close iCloud with Task Manager. You can do that by following these steps:

  1. Press Ctrl + Shift + Esc to start Task Manager.
  2. When Task Manager starts, find iCloud, right-click it and choose End Task.
    Class not registered Windows 10 Photos

In addition, you can also disable iCloud from starting up by using Task Manager.

  1. Open Task Manager and go to the Startup tab.
    Class not registered regsvr32
  2. Find iCould, right-click it, and choose Disable.
    Class not registered PDF

If you want to know more about how to add or remove startup apps, take a look at this in-depth article.


Can’t open Task Manager? Don’t worry, we’ve got the right solution for you.


2. Re-register ExplorerFrame.dll file

If Internet Explorer keeps crashing while giving you the Class not registered error, you might want to try the following:

  1. Open Command Prompt as administrator. To do that press Windows key + X and choose Command Prompt (Admin) from the menu.
    Class not registered PDF
  2. When Command Prompt starts, paste the following code and press Enter to run it:
    regsvr32 ExplorerFrame.dll
    Class not registered msstdfmt.dll

    If you’re having trouble accessing Command Prompt as an admin, you better take a closer look at this guide.


    3. Use Component Services

    To run Component Services do the following:

    1. Press Windows Key + R and type dcomcnfg. Press Enter or click OK to run it.
      Class not registered error videos
    2. When the Component Services window opens, go to Component Services > Computers > My Computer. Double click DCOM Config.
      Class not registered Internet Explorer
    3. You should get a few warning messages. If that happens, just click Yes.
    4. Now close Component Services and restart your computer.

    After doing that, this error message should stop appearing.


    4. Create a new Microsoft account

    If there’s no other way to fix Class not registered error, you might want to create a new Microsoft account on Windows 10.

    1. Go to the Settings app. You can open the Settings app quickly by using Windows Key + I shortcut.
    2. When the Settings app opens, navigate to the Accounts section.
      Class not registered msstdfmt.dll
    3. In the right pane, choose Family & other people from the menu on the left. In the right pane, click on Add someone else on this PC.
      Class not registered error when opening pictures
    4. Enter your Microsoft account email and click Next.
      Class not registered Windows 10 Photos
    5. Log out of your current account and switch to a new one.

    If you’re having trouble opening the Setting app, take a look at this article to solve the issue.


    Windows won’t let you create a new account? Don’t worry, we’ve got you covered.


    We have to mention that this solution might not work unless you choose to sign in with a local account instead. To switch to the local account, follow these steps:

    1. Open Settings > Accounts.
    2. Click Sign in with a local account instead. You’ll be asked to enter your password.
      Class not registered Taskbar
    3. After doing that, you’ll have to enter the username and password for your local account.
    4. Click Sign out and finish button. Now log back to your account.

    After you’ve switched to a local account, repeat the steps from the beginning of this solution.


    5. Check your hard drive

    In some rare cases, Class not registered error can be caused by a faulty hard drive, so make sure that your hard drive is working properly. Few users have reported that replacing their hard drive has fixed this issue for them.


    In the market for the fastest hard drives around? Don’t waste another minute and get the best ones here.


    Class Not Registered on Microsoft Edge

    1. Set Edge / Internet Explorer as default browser
    2. Check if Internet Explorer ETW Collector Service is running

    1. Set Edge / Internet Explorer as default browser

    It has been reported that Class not registered error appears when users are searching the web using Cortana, and in order to fix this, you need to set Edge as a default browser. To do that, follow these instructions:

    1. Press Windows Key + S and type control panel. Choose Control Panel from the list of results.
      Class not registered PDF
    2. Control Panel window will now appear. Select Default Programs from the list.
      Class not registered msstdfmt.dll
    3. When the Default Programs window opens, select Set your default programs.
      Class not registered error when opening pictures
    4. Navigate to the Web browser section and click on your browser.
      Class not registered Microsoft Edge
    5. Select Microsoft Edge from the list.
      Class not registered error when opening pictures

    Can’t open Control Panel on Windows 10? Take a look at this step-by-step guide to find a solution.


    Some users have reported that they are unable to open anything on their desktop, and to fix this it’s advised to set Internet Explorer as the default browser.

    You can do that by following the steps that we described above, or by following these steps:

    1. Open the Settings app and go to the Apps section.
      Class not registered Windows 10 Photos
    2. From the pane on the left select Default apps.
    3. Go to Web browser section set Internet Explorer as the default browser.

    After setting Internet Explorer or Microsoft Edge as the default browser, the problem should be completely resolved.


    2. Check if Internet Explorer ETW Collector Service is running

    Class not registered error often affects Internet Explorer and Microsoft Edge, so if you’re having this problem with these browsers, try the following:

    1. Press Windows Key + R to open the Run dialog. Now enter services.msc and press Enter or click OK.
      Class not registered msstdfmt.dll
    2. In the list of services find Internet Explorer ETW Collector Service, right-click it, and choose Start.
      Class not registered error when opening pictures

    Once you start this service, the problem should be completely resolved.


    Explorer.exe Class Not Registered

    Restart explorer.exe

    If you have problems with Edge, Cortana, or Start menu, it’s advised that you try restarting explorer.exe. To restart explorer.exe do the following:

    1. Start Task Manager and go to the Details tab.
      Class not registered explorer.exe
    2. Find explorer.exe and right-click it. Choose End Task from the menu.
      Class not registered PDF
    3. Now in Task Manager go to File > Run new task.
      Class not registered msstdfmt.dll – DLL files can sometimes cause this issue, and if you experience it on your PC, be sure t
    4. Create new task window will appear. Type explorer and press Enter or click OK.
      Class not registered error when opening videos
    5. Explorer will start again, and everything should be working.

    Sometimes, Task Manager is slow or responds with delay. If you have this problem as well, we recommend you to take a look at this step-by-step guide to speed up your Task Manager’s responsiveness.


    Error Class Not Registered with JPG files

    1. Change default image viewer to Windows Photo Viewer
    2. Reset default apps

    1. Change default image viewer to Windows Photo Viewer

    As we already mentioned Class not registered error can appear when you try to view .jpg files, and if this happens, you might want to set your default image viewer to Windows Photo Viewer. To do that, follow these simple instructions:

    1. Download and run this file. It’s a .reg file that will change your registry and enable Windows Photo Viewer on your computer.
    2. Find any picture on your computer and right-click it.
    3. From the menu choose Open with > Choose another app.
      Class not registered Windows 10 Photos
    4. Select Windows Photo Viewer from the list. If you want to use only Windows Photo Viewer to view pictures, make sure that you select Always use this app to open .jpg files. Click OK to save changes.
      Class not registered Excel

    If you don’t want to add any changes to your registry, you can simply download any free image viewing software, install it on your computer and repeat all steps starting from Step 2.


    Need more info on how to use Windows Photo Viewer on Windows 10? Check out this article.


    2. Reset default apps

    According to users, Class not registered error appears when they try to open a .jpg file on their computer, and this problem can be fixed by resetting default apps. To do that, follow these instructions:

    1. Open Settings > Apps > Default apps.
    2. Scroll down until you see Reset to the Microsoft recommended defaults. Click the Reset button.
      Class not registered PDF

    If you can’t change the Windows default apps, check out this article that will help you do just that.


    Class not registered error can cause all sorts of problems on your computer, but we hope that our solutions have fixed this issue for you.

    If you have any more questions, feel free to drop them in the comments section below.

FAQ: Learn more about Explorer.exe class not registered

  • What does class not registered mean on Windows 10?

Class not registered msstdfmt.dll is usually caused by DLL files becoming unregistered. This error can affect any app from the Photos app, Media Player, Taskbar, Outlook, IE, Edge, and so on since Windows cannot link the app to its associated DLL files.

  • How do I fix a non registered class?

From creating a new Microsoft account to restarting Explorer.exe, there are a few methods to fix this error. Check out this full guide for step-by-step explanations.

  • What does Explorer EXE mean?

EXPLORER. EXE is the executable file of the Windows OS GUI. It’s a legitimate Microsoft process that automatically runs at startup and is essential for the proper functioning of Windows. If your File Explorer crashes fro some reason, follow these steps to restore it.

Editor’s Note: This post was originally published in January 2018 and has been since revamped and updated in May 2020 for freshness, accuracy, and comprehensiveness.

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