Outlook Keeps Asking for Password: How to Fix It

You type your password into Outlook, it accepts it, and then thirty seconds later it asks again. Or it shows a password prompt every single time you open it, no matter what you do. This loop is one of the most common Outlook problems reported by Microsoft 365 users on Windows 10 and 11 — and it’s almost never about forgetting your password. The cause is nearly always authentication, credential storage, or account configuration. Here’s how to fix it.

Understand Why This Happens

The repeated password prompt usually means one of three things: Outlook can’t contact the authentication server, it has stale or corrupted credentials stored in Windows, or there’s a conflict between the authentication method your organisation or Microsoft 365 expects and what Outlook is trying to use.

Microsoft 365 now uses modern authentication (OAuth 2.0) by default. If Outlook is configured to use basic authentication — which older setups sometimes default to — the login tokens don’t get stored correctly and the prompt keeps reappearing. MFA and Conditional Access policies can also trigger this when something in the session breaks.

Step 1: Clear Stored Credentials in Windows Credential Manager

This is the fix that works most often. Windows stores Outlook credentials in the Credential Manager, and if those entries are stale, incorrect, or duplicated, Outlook gets confused and keeps prompting.

1. Close Outlook completely
2. Open the Start menu and search for Credential Manager
3. Click Windows Credentials
4. Look for any entries that mention MicrosoftOffice, Outlook, Office 365, or your email address
5. Click each one and select Remove
6. Also look for entries beginning with msteams, Microsoft_OC, or Office16 — remove these too
7. Reopen Outlook and sign in fresh when prompted

After signing in, Outlook should store new credentials and stop prompting. If it works initially but the prompt returns the next day, that points to a Modern Auth issue — continue reading.

Step 2: Enable Modern Authentication

If you’re using a Microsoft 365 account, Outlook should be using modern authentication (OAuth), not basic authentication. Basic auth sends credentials directly and doesn’t support the token-based sessions that prevent repeated prompts.

To check and enable it via the Windows Registry:

1. Press Win + R, type regedit, and press Enter
2. Navigate to: HKEY_CURRENT_USERSoftwareMicrosoftOffice16.0CommonIdentity
3. If the Identity key doesn’t exist, right-click Common and create it
4. Inside Identity, create a new DWORD (32-bit) Value named EnableADAL
5. Set its value to 1
6. Create another DWORD named Version and set it to 1
7. Close the registry editor and restart Outlook

This forces Outlook to use the modern authentication stack. Sign in when prompted — you should get a proper Microsoft login window rather than the old-style username/password box.

Step 3: Check Your Microsoft 365 Account in Outlook Settings

Sometimes the issue is that Outlook has the account set up incorrectly — particularly if someone migrated from an on-premises Exchange server to Microsoft 365 and the old server details are still in the configuration.

1. Go to File > Account Settings > Account Settings
2. Double-click your email account
3. Check the server address — for Microsoft 365 it should show outlook.office365.com
4. If you see an old on-premises Exchange server address, remove the account and re-add it fresh

To remove and re-add: go to File > Account Settings > Account Settings, select the account and click Remove, then Add and enter your email address. Outlook will auto-discover the correct settings for Microsoft 365 accounts.

Step 4: Sign Out of Office Completely

If the credentials are cached at the Office application level — not just Credential Manager — a full sign-out and sign-in can clear the loop.

1. In Outlook, go to File > Office Account (or File > Account)
2. Click Sign Out next to your account name
3. Close Outlook
4. Reopen it and sign in again

You may also want to do this in other Office apps — Word, Excel, Teams — if you’re signed in there too, as they share the same credential token pool.

Step 5: MFA and Conditional Access Loops

If your organisation uses Multi-Factor Authentication or Conditional Access policies (common in business Microsoft 365 tenants), the password loop can appear when your authentication token expires or your device falls out of compliance.

Signs this is the cause: the Outlook password prompt appears suddenly even though nothing changed on your end, other Microsoft 365 apps like Teams also start behaving oddly, or you get a message mentioning “your organisation requires additional verification.”

• Open a browser and sign into portal.office.com — if MFA prompts you here, complete it and then retry Outlook
• Check whether your device is enrolled in Azure AD or Intune if your organisation manages devices — a lapsed enrolment can trigger this
• Contact your IT administrator if Conditional Access policies have recently changed — they may need to update the policy or re-register your device

Step 6: Recreate the Outlook Profile

If all else fails, a corrupted Outlook profile can cause persistent authentication failures. Creating a fresh profile forces Outlook to start clean and re-establish authentication from scratch.

1. Close Outlook
2. Open Control Panel and click Mail (Microsoft Outlook)
3. Click Show Profiles > Add
4. Name the new profile and click OK
5. Add your email account to the new profile
6. Set Outlook to prompt for profile on startup so you can test the new one without deleting the old one yet

If the new profile signs in cleanly without prompting, your old profile was the problem. You can set the new profile as the default and remove the old one.

Windows 11 Specific: Account Sync Settings

Windows 11 has a separate layer of Microsoft account integration that can interfere with Outlook credentials, particularly on personal machines running Microsoft 365 Family or Personal.

1. Go to Settings > Accounts > Email & accounts
2. Check whether your Microsoft account or work/school account is listed here
3. If it shows a warning icon or says “Fix now,” click it and follow the re-authentication steps
4. Once the Windows account is refreshed, reopen Outlook and test

A Note on Classic vs New Outlook

The new Outlook (the web-wrapped version available as a toggle in Windows 11) handles authentication differently. If you’re experiencing password loops there, sign out from within the app via Settings > Accounts, then sign back in. The new Outlook relies entirely on modern auth, so the registry tweak above isn’t needed — but clearing credentials from Windows Credential Manager still applies.

Repeated password prompts are fixable in the vast majority of cases. Start with Credential Manager, enable modern auth if needed, and work through the steps above. In business environments with MFA or Conditional Access, the fix is usually a re-authentication or an IT policy adjustment — but it’s rarely anything more serious than that.

For a full index of every Outlook guide and troubleshooting fix on Serverman, see the Microsoft Outlook complete guide and troubleshooting hub.