How to Fix Office 365 Sign-In Failure After a Windows 10 Upgrade
Question details
The user needs to fix an issue where Office desktop applications prompt an account error and fail to sign in after a Windows 10 feature upgrade, despite the web login working correctly.
- Product
- Microsoft Office 365
- Device & OS
- Windows 10
- Scenario
- Attempting to open and authenticate Microsoft Office desktop applications such as Word or Excel following a recent Windows 10 system upgrade.
- Observed behavior
- Office desktop applications display account errors and fail to sign in due to retained damaged credentials or identity data from before the OS upgrade.
Ensure you have administrator privileges on your computer, as you will need to access the Windows Credential Manager and the Registry Editor to clear corrupted authentication data.
Clear Office Credentials and Reset Registry Identities
Removing cached credentials and clearing corrupted identity data in the Windows Registry is the most effective way to resolve post-upgrade sign-in conflicts.
During a major Windows update, cached login tokens for Office can become invalid or corrupted. Deleting these old credentials forces the application to request a fresh, secure connection from Microsoft's servers.
Open the Control Panel, navigate to 'User Accounts', and select 'Credential Manager'. Click on 'Windows Credentials', locate any entries starting with 'MicrosoftOffice', and click 'Remove'.
Close all Office applications. Press the Windows Key + R, type 'regedit' into the Run dialog box, and press Enter to launch the Registry Editor.
Navigate to the following path: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities. Right-click the 'Identities' folder and select 'Delete'.
Restart your computer. Once Windows loads, open Word or Excel and follow the prompts to sign in with your Microsoft 365 work account.
Perform an Online Repair for Office
If resetting credentials does not work, the Windows 10 upgrade may have corrupted the Office installation files, requiring an online repair.
Use WPS Office to Avoid Account Sign-in Hassles
Tired of dealing with complex registry edits and persistent sign-in errors after Windows updates? Switch to WPS Office, a lightweight, free alternative that offers a hassle-free experience with seamless compatibility with Microsoft formats.
- 1. Download the Installer: Visit the official WPS Office website and click the free download button for Windows.
- 2. Install the Software: Run the downloaded setup file and follow the quick installation prompts.
- 3. Open and Edit Immediately: Launch WPS Office and start working on your existing documents without needing to troubleshoot account sign-ins.
Frequently Asked Questions
Why does Office 365 say 'Account Error' after a Windows 10 update?
During a Windows feature upgrade, the cached credentials or registry identity keys for Office can become misaligned or corrupted. This prevents the desktop apps from authenticating locally, even if your account works fine on the web version.
Will deleting the Identities folder in the registry delete my Office files?
No. Deleting the Identities folder only removes your localized login session data. Your documents, settings, and personal files are completely safe. Office will simply prompt you to sign in again to recreate the profile.
What should I do if the Online Repair tool gets stuck?
If the Online Repair hangs, ensure you have a stable internet connection. If the issue persists, cancel the process and use the Microsoft Support and Recovery Assistant (SaRA) tool to cleanly uninstall and reinstall Office 365.
