How to switch back to outlook classic?

Hello Zhou,

Thank you for explaining the issue.

Microsoft documents that when the New Outlook setting is enabled, selecting Outlook (classic) from the Windows Start menu can still redirect you to New Outlook.

Let's first check the switching preference.

1. Switch back to Classic Outlook
2. Open New Outlook.

Locate the New Outlook toggle in the upper-right corner.

Select the toggle.

Choose Switch back to classic Outlook.

Complete or skip the feedback prompt if requested.

Once the process is complete, open the Windows Start menu, search for Outlook (classic), and launch the application without the New label.

One important distinction: select Switch back to classic Outlook, not Use classic Outlook this time. The second option only opens Classic Outlook for the current session. Future launches can still redirect to New Outlook.

2. If the toggle is missing

Microsoft provides an alternative through the Windows Registry:

Close Outlook.

Open the Windows Start menu, search for Registry Editor, and open it.

Navigate to:

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

Locate the UseNewOutlook value.

Double-click it and set Value data to 0.

Select OK.

Open the Windows Start menu and launch Outlook (classic).

This setting disables the automatic switching preference. Please take care when editing the Registry, and avoid changing other values. If this is an organization-managed device, check with your IT administrator before making Registry changes.

For reference, Microsoft's instructions are available here:

Toggle out of the new Outlook for Windows

Start new users in new Outlook – Microsoft Learn

Could you confirm whether you can see the New Outlook toggle in the upper-right corner? If it is visible, does selecting “Switch back to classic Outlook” resolve the issue, or does New Outlook still open when you launch Classic Outlook again?

That will help narrow down the next troubleshooting step.

Best regards,

How to Switch Back to Classic Outlook

If classic Outlook keeps opening the new version, you can resolve the redirection and switch back permanently using these methods:

Method 1: Turn off the toggle in New Outlook

Open new Outlook.

Select the New Outlook toggle in the upper-right corner.

Choose Switch back to classic Outlook (make sure not to select Use classic Outlook this time, as it is only temporary).

Complete or dismiss the feedback prompt.

Open Start, search for Outlook (classic), and select the icon without the "New" label.

Method 2: Update the Registry (If redirection continues)

If selecting classic Outlook still forces it to open the new version, you can reset the preference via the Registry:

Close both Outlook applications.

Open Start, search for Registry Editor, and open it.

Navigate to the following path:Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Preferences

Double-click UseNewOutlook.

Set the Value data to 0, then click OK.

Launch Outlook (classic) from the Start menu.

Note: Registry changes can affect application behavior; change only this documented value.

Additional Troubleshooting

• If “Outlook (classic)” is missing from Start: Classic Outlook may not be installed on your device. You can install or reinstall it using the Install or reinstall classic Outlook on a Windows PC guide, then launch it from the Start menu.
• Pin to Taskbar: Once classic Outlook opens correctly, right-click its icon in the Start menu and select Pin to taskbar, and remove the new Outlook shortcut to avoid launching the wrong app in the future.