I want Outlook to stop switching me from classic Outlook to new Outlook

Question

I was forced to use Microsoft 365 because it wouldn't let me load Outlook 2019 on my new computer. I switched to Classic Outlook (new outlook is HORRIBLE....buggy....doesn't work with ProSeries or Sage 50 and I was unable to save contacts. When I say HORRIBLE......I MEAN HORRIBLE!!) Anyway, several times a day Outlook switches itself back to the new Outlook.

How do I stop this from happening? There is a thread that addresses this, but it's applicable to those who hadn't been forced to already migrate to the new (HORRIBLE) Outlook.

Answer 1

Dear @Martin Harris,

Thank you for reaching out to the Microsoft Q&A forum. I’m happy to assist you.

If you would like to continue using the classic Outlook experience without switching back to the new Outlook interface, please try the following steps:

Open Classic Outlook from the Start Menu

Use the Windows search bar to look for “Classic Outlook.” Select and open the classic Outlook application. This may help prevent automatic switching to the new Outlook.

Modify the Registry Settings

From the Windows Start Menu, type Registry Editor in the search box and open the Registry Editor app.

Navigate to the following path:

Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Preferences

Scroll to the bottom of the list and double-click on UseNewOutlook.

In the Value Data field, enter 0, then click OK.

If the key does not exist, you can create it and set its value to 0. Right-click in the blank area, select New > DWORD (32-bit) Value, and name it UseNewOutlook.

Close the Registry Editor and restart your device.
After restarting, attempt to open Classic Outlook from the Windows Start Menu.

Uninstall new outlook

If neither option works, you can uninstall the New Outlook app from your device. 

1. To do this, go to Windows Settings > Apps > Installed apps, find New Outlook, and select Uninstall. 
2. After removing it, you can continue using the classic Outlook installed on your system. 

 

Please note that if you’re using a work account, your organization may have applied a policy that enforces the New Outlook experience. In that case, you’ll need to contact your IT admin to review this setting.

Since I do not have access to your device environment, there may be cases where my recommended solutions do not fully resolve the issue or other problems appear. If that happens, please update me right away with any new details or results in the Comment. I will do my best to support you and help find a solution as quickly as possible.

---

If you found the answer useful, please click "Accepted Answer" and kindly give it an upvote.

If you have any follow-up questions, feel free to click "Comment" to continue the discussion.

Note: To receive email notifications related to this thread, please follow the steps in our documentation to enable email alerts.

Answer 2

To prevent Outlook from automatically switching from Classic Outlook to New Outlook, you can opt out of the automatic migration process. Here’s how you can do this:

1. Opt-out through Outlook Options: You can go to Outlook Options > General and opt out of the automatic migration to the new Outlook. This setting should help maintain your use of Classic Outlook without it switching back.
2. Admin Control: If you are in an organization, your administrator can also disable the automatic migration setting. They can configure the policy to prevent users from being switched to the new Outlook. This can be done through the Microsoft 365 Apps admin center or using Group Policy.
3. Registry Settings: If you have access to modify the Windows registry, you can set the following registry key to disable automatic migration:

      [HKEY_CURRENT_USER\Software\Policies\Microsoft\office\16.0\outlook\preferences]
      "NewOutlookMigrationUserSetting"=dword:00000000
   

   This will prevent the automatic migration to the new Outlook.

By following these steps, you should be able to stop Outlook from switching back to the new version automatically.

---

References:

• Opt out of new Outlook migration
• Control installing and using new Outlook