Unable to sign in to Office 365 (even with correct password)

Trying to sign in to Office 365 with the right password, but still getting blocked? That’s annoying, and it happens more often than you’d think. Usually, the culprit isn’t the password itself. Instead, cached credentials, account sync hiccups, or outdated authentication settings tend to cause these headaches. The upside? You can usually spot and fix these issues without too much trouble.

We see businesses run into this problem all the time, and it’s a real pain when you can’t get into your email, Teams, or any other Microsoft 365 service. Let’s run through some quick checks, common fixes, and a few advanced tricks so you can get back to what you need to do.

Every company’s setup is a little different, and sometimes the problem goes deeper than resetting a password. If you’re stuck and want someone to jump in, our crew at NetTech Consultants – IT Support and Managed IT Services in Jacksonville can help. We’ll work with you to find a fix that matches your business.

Immediate Steps When Unable to Sign In

If you can’t get into Microsoft 365 with the right password, there’s a good chance something’s off with your credentials, the way you’re typing things in, or the status of your account. Checking these basics first can save a lot of time before you dive into deeper troubleshooting.

Verify Microsoft 365 Account Credentials

First, double-check that you’re using the right Microsoft 365 account. Lots of people have more than one—maybe a personal Microsoft account plus a work or school one. Mixing them up is easy and can cause sign-in trouble.

If you’re sure the password is right but it still won’t let you in, try resetting it using the Microsoft 365 password reset portal. That way, you make sure your account syncs up with Microsoft’s authentication system.

Clearing cached credentials can help, too. On Windows, head to Credential Manager, remove any saved Office 365 entries, then try signing in again. This wipes out old or conflicting login info that might be blocking you.

Also, check your multi-factor authentication (MFA) setup. If MFA is on, make sure you’ve got access to the device or app you need to approve the login.

Check Keyboard Layout and Input Issues

Typos and input mistakes trip people up more than you’d think. Make sure your keyboard layout is set to what you expect, especially if your computer has more than one language installed. Sometimes, a different layout will mess up special characters in your password.

On Windows, pressing Windows + Spacebar lets you switch between keyboard layouts. Pick the right one before typing your password to avoid getting locked out.

Don’t forget to check if Caps Lock or Num Lock is on. Those can change your input and you might not notice right away. You can test your password in a plain text field (not the login box) to see if it comes out right.

If you’re copying and pasting your password, watch out for extra spaces sneaking in. Typing it by hand is usually safer.

Confirm Account Status and Licensing

Even if your credentials are fine, your Microsoft 365 account won’t work if your subscription is inactive or your license isn’t set up right. Check your account status in the Microsoft 365 admin center.

If your account is disabled or unlicensed, you won’t be able to get in until an admin fixes it. Expired subscriptions or suspended accounts are often behind these issues.

In business settings, group policies and conditional access rules can cause problems, too. Restrictions on device compliance, location, or sign-in risk might block you even if your password is correct.

If you’ve checked all this and still can’t sign in, reach out to your Microsoft 365 admin or support team. They can help figure out if the problem is just with your account or something bigger.

Troubleshooting Common Sign-In Problems

If you’re still locked out of Office 365 with the correct password, the issue probably isn’t your account. We often see problems with cached credentials, a corrupted Office install, or some configuration error in Windows 11.

Remove Stored Credentials via Control Panel

Clearing out old or wrong login info from the Windows Credential Manager is a good place to start. Cached credentials can keep the password prompt from showing up or cause repeated sign-in failures.

Open the Control Panel and go to Credential Manager. Click on Windows Credentials and look for anything related to Microsoft Office or Microsoft 365.

Remove each relevant entry. You might have a few, so clear out all Office-related ones.

After that, restart your computer and try signing in again. This usually forces Office 365 to ask for your credentials again, which can clear up the problem.

Repair Microsoft 365 Installation

If clearing credentials doesn’t do the trick, your Office installation might be corrupted. Running a repair can fix missing or damaged files without reinstalling everything.

Go to Control Panel, open Programs and Features, and find Microsoft 365 Apps. Right-click, pick Change, then go for Quick Repair.

Quick Repair sorts out most issues fast. If it doesn’t, try Online Repair. That one takes longer and needs an internet connection, but it digs deeper and reinstalls components if needed.

We usually suggest Online Repair if you’re seeing sign-in issues in more than one Office app like Outlook and Word.

Use Microsoft 365 Sign-In Troubleshooter

Microsoft has a built-in sign-in troubleshooter that can spot and fix common authentication problems. This tool comes in handy for Windows 11, where new authentication settings or local setup quirks might get in the way.

Download the troubleshooter from Microsoft Support. Run it, follow the instructions, and let it scan for issues with cached tokens, registry settings, or system policies.

The tool gives you results and fixes what it can automatically. If you need to make manual changes, it’ll give you clear steps to follow.

Advanced Solutions for Persistent Issues

If the usual troubleshooting doesn’t solve your Office 365 sign-in problems, you might need to dig a bit deeper. Sometimes, authentication settings, Windows account configuration, or a corrupted profile can block you even with the right password.

Disable Modern Authentication Using Registry Editor

Modern authentication boosts security, but sometimes it stops the password prompt from popping up in Office apps. In some cases on Windows 11 or 10, switching back to legacy authentication does the trick.

Tread carefully here, since this changes how all Office apps handle sign-ins. Open Registry Editor as an admin to make the change.

Steps:

1. Press Windows + R, type regedit, and run as administrator.
2. Go to:
   HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity
3. Create a new DWORD (32-bit) Value called EnableADAL.
4. Set the value to 0 (Hexadecimal).
5. Restart your computer and try signing in again.

This turns off modern authentication for Office apps, letting the system use legacy methods. If you can sign in after this, modern authentication was likely the issue.

Switch to a Local Windows Account

A corrupted Microsoft-linked Windows profile can block Office 365 sign-in. One way to check is to sign in with a local Windows account. Making a new profile helps make sure cached credentials or profile-specific glitches aren’t messing things up.

To set up a local account:

1. Open Settings > Accounts > Family & other users.
2. Click Add someone else to this PC.
3. Pick I don’t have this person’s sign-in information.
4. Click Add a user without a Microsoft account.
5. Set a username, password, and security questions.

Restart, then log in with the new account and open an Office app. If the password prompt shows up like it should, your old profile was probably corrupted. If this works, moving your data to the new account is usually the way to go.

Address GUID and Profile Corruption

Sometimes, Office 365 sign-in just won’t work because the GUID tied to a Windows profile gets messed up. When this happens, Windows can’t really connect your identity to Office services the way it’s supposed to.

Here’s what usually helps: check the registry and get rid of any profile identifiers that look off. If that doesn’t do the trick, setting up a new profile is usually the safest bet.

Try these steps:

• Open Registry Editor and head to:
  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
• Look through the subkeys, which show user profiles by their GUIDs.
• Watch for profiles with missing or wrong paths.
• Once you’re sure which profile is good, go ahead and remove or rename the broken entries.

After you fix the GUID problem, Windows should link the account and Office 365 properly again. Most of the time, you’ll be able to sign in without those annoying failures.