Outlook Cannot Add Microsoft 365 Account After Password Change: Fix

After changing your Microsoft 365 password, Outlook may refuse to add your account again. The error often appears as a repeated password prompt or a message that Outlook cannot connect to the server. This happens because Outlook caches old credentials in Windows Credential Manager and in the registry. This article explains why the cached data blocks the new password and provides a complete fix to remove the old credentials and add your account successfully.

Why Outlook Cannot Add a Microsoft 365 Account After a Password Change

When you change your Microsoft 365 password, Outlook does not automatically fetch the new credential. Instead, Outlook continues to use the old password stored in Windows Credential Manager. This credential cache is located under two main entries: one labeled “MicrosoftOffice16_Data:ADAL:” and another labeled “Microsoft.AAD.BrokerPlugin.“. Both entries store the previous authentication token.

The second reason is that Outlook’s profile may contain a corrupted or stale authentication state. The profile is stored in the Windows registry under HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Profiles. If the profile has broken settings, Outlook cannot complete the modern authentication handshake with Microsoft 365 servers. The server sees the request as coming from a device with an expired or invalid token and rejects the connection.

A third cause is the Outlook cached mode data file (.ost). If the OST file is associated with the old password and the account is removed, the file may become orphaned. When you try to add the same account again, Outlook may attempt to reuse the old OST file, which contains outdated authentication metadata. Deleting the OST file along with the credentials resolves the conflict.

Steps to Clear Credentials and Re-add Your Microsoft 365 Account

Follow these steps in order. Do not skip any step. Each step removes a layer of cached data that blocks the new password.

Step 1: Remove Stored Passwords from Windows Credential Manager

1. Open Credential Manager
   Press the Windows key and type “Credential Manager”. Click the result that appears under Control Panel.
2. Switch to Windows Credentials
   Click the button labeled “Windows Credentials” at the top of the window.
3. Locate Microsoft 365 related entries
   Scroll through the list under “Generic Credentials”. Look for entries that contain:
   – “MicrosoftOffice16_Data:ADAL:” followed by a GUID
   – “Microsoft.AAD.BrokerPlugin:” followed by your email address
   – Any entry that starts with “MicrosoftOffice16” and contains your account name
4. Remove each entry
   Click the arrow to expand the entry, then click “Remove”. Confirm the deletion when prompted. Repeat for every entry that matches the patterns above.
5. Close Credential Manager
   Exit the window after removing all relevant entries.

Step 2: Delete the Outlook Profile from the Registry

1. Open Registry Editor
   Press Windows key + R, type “regedit”, and press Enter. Click Yes if User Account Control asks for permission.
2. Navigate to the Outlook Profiles key
   In the left pane, expand the following path:
   HKEY_CURRENT_USER > Software > Microsoft > Office > 16.0 > Outlook > Profiles
3. Identify the old Outlook profile
   Under the Profiles key, you will see one or more subkeys. Each subkey is a named Outlook profile, such as “Outlook” or “Default Outlook Profile”. If you are unsure which profile is causing the issue, note the name of the profile you are trying to add the account to.
4. Delete the profile subkey
   Right-click the subkey that corresponds to the problematic profile and select “Delete”. Confirm the deletion. Do not delete the entire Profiles key — only the subkey for the specific profile.
5. Close Registry Editor
   Exit the editor. No restart is required.

Step 3: Delete the OST File

1. Open File Explorer
   Press Windows key + E.
2. Navigate to the Outlook data folder
   Paste this path into the address bar and press Enter:
   %localappdata%\Microsoft\Outlook
3. Locate the OST file
   Look for a file with the .ost extension that matches your email address or the profile name. The file name is usually your email address followed by “.ost”.
4. Delete the OST file
   Right-click the file and select “Delete”. Confirm the deletion. Outlook will recreate this file automatically when you add the account again.
5. Close File Explorer
   Exit the window.

Step 4: Remove the Old Profile from Control Panel

1. Open Mail in Control Panel
   Press Windows key + R, type “control”, and press Enter. In Control Panel, set “View by” to “Large icons” and click “Mail (Microsoft Outlook)”.
2. Open Show Profiles
   Click the “Show Profiles” button.
3. Remove the old profile
   Select the profile you identified earlier from the list. Click “Remove” and confirm the deletion.
4. Close Mail settings
   Click OK to exit the Mail dialog.

Step 5: Add Your Microsoft 365 Account in Outlook

1. Open Outlook
   Launch Outlook. If no profile exists, Outlook will prompt you to create one. Click “Next” to start the automatic account setup.
2. Enter your email address
   Type your Microsoft 365 email address and click “Connect”.
3. Enter your new password
   When prompted, type your new password. Check the box “Remember my credentials” if you want Windows to store the new password securely.
4. Complete the setup
   Outlook will test the connection and configure the account. This process may take a few minutes. When done, click “Finish”.

If Outlook Still Has Issues After the Main Fix

Outlook prompts for password repeatedly after re-adding the account

This indicates that a cached credential entry was missed in Credential Manager. Return to Step 1 and check for any remaining entries that contain “ADAL” or “AAD”. Also check entries under the “Web Credentials” tab in Credential Manager. Remove any that reference your email address or Microsoft 365 tenant. Then restart Outlook.

Outlook shows error 0x80070005 when trying to add the account

This error means Outlook cannot access the registry or the OST file location due to permission issues. Run Outlook as administrator once to reset permissions. Right-click the Outlook shortcut and select “Run as administrator”. After the account is added, close Outlook and open it normally. If the error persists, check that your Windows user account has full control over the %localappdata%\Microsoft\Outlook folder. Right-click the folder, go to Properties > Security, and verify your user account has Modify permission.

Outlook cannot connect to the server even with the correct new password

This usually points to a network or firewall issue. Verify that your internet connection is active. Check if other Microsoft 365 services like Outlook Web Access (OWA) work with the new password. If OWA works but Outlook does not, the problem is likely a cached credential that was not deleted. Repeat all five steps. Also check if your organization requires multi-factor authentication. If MFA is enabled, you may need to create an app password or use the Microsoft Authenticator app to complete the sign-in process. Contact your IT administrator for MFA-specific instructions.

Cached Credential Removal vs Full Profile Reset: Key Differences

Item	Credential Manager Removal	Full Profile Reset
Description	Deletes stored passwords and tokens from Windows	Removes the entire Outlook profile including all accounts, data files, and settings
Time required	5 to 10 minutes	15 to 30 minutes
Data loss	No data loss — only credentials are removed	Local cached data (OST file) is deleted; server data remains intact
When to use	Password change, repeated credential prompts, authentication errors	Corrupted profile, missing folders, persistent sync issues after credential fix
Effect on other apps	May affect other Microsoft 365 apps (Teams, OneDrive) that use the same cached token	No effect on other apps — only Outlook profile is removed

After completing the credential removal and re-adding your account, Outlook will synchronize your mailbox from the server. The first sync may take longer than usual because Outlook downloads the entire mailbox again. To speed up the initial sync, set the cached mode slider to a shorter period such as 1 month. Go to File > Account Settings > Account Settings, select your account, click Change, and drag the slider under Offline Settings to 1 month. This reduces the amount of data Outlook downloads initially.

If you have multiple Microsoft 365 accounts in the same Outlook profile, repeat the credential removal for each account. Each account stores its own set of credentials in Credential Manager. After removing all entries, add each account back one at a time. Use the same five-step process for each account to avoid mixing old and new credentials.