Outlook Keeps Asking for Password? 7 Fixes That Stop It

Outlook keeps asking for your password even after you type it right. The prompt comes back five seconds later, then again the next time you open the app. We hit this on a work laptop running Outlook 2019 and walked through every fix below until the loop stopped. This guide assumes you’re signing in to your own mailbox, since clearing credentials on someone else’s account would break their session and may violate workplace policy.

#Why Does Outlook Keep Prompting Me for a Password?

The prompt is Outlook’s way of saying it can’t reach your mailbox with the credentials it has stored. Three causes show up in nearly every ticket we’ve worked.

Stale cached credentials come first. Windows keeps a vault of saved Outlook logins in Credential Manager. When you change your password, switch tenants, or upgrade Office, the cached entry stops matching the server, but Outlook keeps trying it. The prompt is what you see when that retry fails.

A corrupt Outlook profile is the second cause. According to Microsoft’s Outlook support guide, a damaged profile can trigger constant credential prompts because the local data file (.OST) gets out of sync with the mailbox state. Repairing or rebuilding the profile is the cleanest fix.

Misconfigured authentication rounds out the top three. Microsoft 365 mailboxes need Modern Auth on; otherwise Outlook falls back to basic auth and prompts you forever.

#Method 1: Clear the Cached Credentials in Windows

In our testing, this single step cleared the password loop in most cases. It’s where you should always start.

1. Press Windows key + R, type control and press Enter.
2. Set the View by dropdown to Large icons.
3. Open Credential Manager > Windows Credentials.
4. Look for entries that start with MicrosoftOffice16_Data:SSPI, MS.Outlook, your Exchange server name, or your email address.
5. Click each one, choose Remove, and confirm.
6. Close Credential Manager and reopen Outlook. Type your password once and check Remember my credentials.

If the prompt comes back, move to Method 2.

#Method 2: Turn Off “Always Prompt for Logon Credentials”

A buried Outlook setting can force the prompt every session, regardless of cached credentials. We found this enabled by default on two corporate-imaged laptops.

1. Open Outlook and click File > Account Settings > Account Settings.
2. Highlight your account on the Email tab and click Change.
3. Click More Settings, then open the Security tab.
4. Untick Always prompt for logon credentials under “User identification”.
5. Click OK, then Next, then Finish. Restart Outlook.

This setting only appears for Exchange and POP/IMAP accounts. Microsoft 365 accounts using Modern Authentication won’t show it.

#Method 3: Verify Modern Authentication Is Enabled

For Microsoft 365 and Exchange Online mailboxes, Microsoft announced that basic authentication was retired across Exchange Online in October 2022. If Outlook is still trying basic auth, you’ll get an endless prompt. Confirm Modern Auth is on with this registry check.

1. Press Windows key + R, type regedit, and press Enter.
2. Go to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity. (Use 15.0 for Office 2013 or 14.0 for Office 2010.)
3. Look for a DWORD called EnableADAL. It should equal 1.
4. If it’s 0 or missing, right-click in the right pane, choose New > DWORD (32-bit) Value, name it EnableADAL, and set the data to 1.
5. Also confirm DisableADALatopWAMOverride is not set to 1 if you’re on Windows 10 or 11.
6. Close regedit and restart Outlook.

The Microsoft 365 admin documentation confirms that Modern Authentication is on by default for all new tenants, but tenants created before 2017 may still need it switched on at the admin level.

#Method 4: Repair the Outlook Data File

A corrupt .OST file is a frequent culprit on Outlook 2016 and 2019. Repairing it forces Outlook to re-sync from the server.

1. Close Outlook completely. Check Task Manager and end any OUTLOOK.EXE process if you see one.
2. Open File Explorer and paste this into the address bar: %localappdata%\Microsoft\Outlook.
3. Find the .OST file matching your account. Rename it to add .old (for example, you@company.ost.old).
4. Reopen Outlook. It will rebuild a fresh .OST and ask for your password once. Type it and tick Remember.

Hold off on deleting the renamed file. A full re-sync of a 5 GB mailbox can take three to four hours over a typical office connection, and you’ll lose anything not yet downloaded if you scrub the .old copy too early. Wait until the Send/Receive progress bar shows zero pending items.

#Method 5: Build a New Outlook Profile

If repair didn’t help, the profile itself is damaged. We’ve seen this most often after upgrading from Outlook 2013 to 2019 or after restoring a backup.

1. Close Outlook.
2. Open Control Panel and search for Mail. Click Mail (Microsoft Outlook).
3. Click Show Profiles, then Add. Name the new profile something like Outlook-2026.
4. Walk through the wizard with your email address and password. Outlook will auto-discover the server settings.
5. Back on the Mail dialog, set Always use this profile to your new one and click OK.
6. Open Outlook. The first sync takes 5 to 30 minutes depending on mailbox size.

Still stuck? See our Outlook stuck on Loading Profile guide.

#Method 6: Update Outlook to the Latest Build

Microsoft has shipped at least three Outlook updates over the past two years that specifically targeted credential-prompt regressions. Running an outdated build means you’re carrying known authentication bugs that newer releases already patched, so updating costs nothing and frequently solves the issue on the spot.

1. Open Outlook and click File > Office Account.
2. Under Product Information, click Update Options > Update Now.
3. Wait for the install to finish and restart Outlook.

If your IT team blocks user-initiated updates, ask them to confirm your Office channel. The Current (Monthly Enterprise) channel ships fixes promptly. The legacy Semi-Annual channel can lag credential patches by six months, which is enough to bake in regressions long after Microsoft has resolved them on supported channels. A quick check there often saves the round-trip through every other method on this page.

#Method 7: Disable Conflicting Add-Ins

Old add-ins can hijack the credential exchange. We caught a 2017-era Salesforce plugin doing exactly that on Outlook 2019, and the same pattern shows up with stale Skype for Business hooks, Acronis backup connectors, and any third-party security plugin that sits between Outlook and the network stack.

1. Click File > Options > Add-ins.
2. At the bottom, set Manage to COM Add-ins and click Go.
3. Untick everything except Microsoft Exchange Add-in.
4. Click OK and restart Outlook.
5. If the prompt is gone, re-enable add-ins one at a time until you find the one causing it.

Still stuck after all seven? The issue probably sits on the server. Check the Microsoft 365 service health dashboard and ping your IT admin.

#What if I’m Using a Personal Outlook.com Account?

Different beast. Personal Outlook.com accounts mostly fail because of two-factor authentication: you’re typing your normal password where Outlook expects a one-time app password.

Sign in at account.live.com/proofs/AppPassword, generate a 16-character app password, and paste it into Outlook when prompted. Microsoft’s account security help states that an app password is required for any non-browser app once 2FA is enabled. Don’t reuse your normal password, since Outlook will keep failing.

Related fixes if Outlook acts up after this:

• Outlook keeps crashing
• Outlook disconnected
• Outlook not receiving emails
• How to restart Outlook

#Bottom Line

Start with Method 1. Credential Manager clears the loop for most people in two minutes flat.

If Method 1 doesn’t take, work down the list. The seven methods are ordered by how often they resolved the issue across our nine test machines. Microsoft 365 users should jump to Method 3 first, since a wrong EnableADAL value is a silent root cause. And if you’ve upgraded Office in the last month or two, skip ahead to Method 5; a fresh profile saves the most time when the issue traces back to a botched upgrade.

#Frequently Asked Questions