Outlook will not open

Question

I use classic outlook. I clicked on new outlook to see the difference and now my email will not open for <PII Removed>@charter.net. How do I fix this

Answer 1

Please note that our forum is a public platform, and I modified your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data. 

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Hi Mike Brady,

I understand that after trying new Outlook, you can no longer open the email account that you previously used in classic Outlook.

Please note that this is a user-to-user forum, so contributors cannot access your account or device.

The Q&A Assist guidance for returning to classic Outlook is accurate. Have you had a chance to try those steps, particularly Switch back to classic Outlook or Use classic Outlook this time? Both options are part of the documented process for returning to classic Outlook.

I would like to ask one clarification: does Outlook itself not open, or does Outlook open but the mailbox does not load? If a message appears, please share its exact wording while removing your email address and any other personal information.

This information will help identify the appropriate next step without repeating the troubleshooting already provided.

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Answer 2

This usually happens because classic Outlook is now redirecting to new Outlook after the toggle was turned on.

Try these steps:

1. Open new Outlook for Windows.
2. In the top-right corner, select the toggle.
3. Choose Switch back to classic Outlook. This turns off the redirect so the next time classic Outlook is opened, it should open the classic app again.
4. If only temporary access is needed, choose Use classic Outlook this time instead.

If the toggle is not visible:

1. Open the Windows Start Menu and make sure the app being launched is Outlook (classic), not new Outlook.
2. If classic Outlook is not installed, install it by following the classic Outlook install guidance for new Windows PCs.
3. If the toggle still does not appear, a registry change can force classic Outlook to open:
   • Open Registry Editor from the Start menu.
   • Go to Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Preferences
   • Open UseNewOutlook and set Value Data to 0.
   • Then launch Outlook (classic) again from the Start menu.

Note: editing the registry can affect Outlook behavior if the wrong key is changed, so only change the value listed above.

If Outlook still will not open after switching back:

1. Press Ctrl+Shift+Esc to open Task Manager.
2. Select Microsoft Outlook and choose End task.
3. Reopen Outlook.
4. If classic Outlook still hangs or will not start, create a new Outlook profile and test with it:
   • Create the new profile using Create an Outlook profile.
   • Close Outlook.
   • Hold Shift while restarting Outlook.
   • In Choose Profile, select the new profile and choose OK.

If the new profile works, the original profile is likely corrupted.

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• Toggle out of the new Outlook for Windows
• You can't open classic Outlook on a new Windows PC
• Outlook for Windows not responding, hangs, freezes, or stops working
• Outlook for Windows not responding, hangs, freezes, or stops working