How to Fix Office 365 Sign-In Error Looping After Reinstall
Question details
The user is unable to access Office applications due to a continuous sign-in loop and account error that persists even after signing out and reinstalling the software.
- Product
- Microsoft Office 365
- Device & OS
- Windows
- Scenario
- Attempting to authenticate an Office 365 account to clear an exclamation mark warning in Office applications.
- Observed behavior
- Clicking 'Sign in again' triggers an endless loop. Reinstalling the application and performing new sign-in attempts do not resolve the account warning.
Ensure you are logged into Windows with an administrator account and create a backup of your Registry before modifying or deleting any system identity keys.
Remove Stale Office Credentials and Product Keys
Clearing corrupted local credentials and resetting the product key from your system usually resolves continuous sign-in loops.
When you uninstall Office, Windows may leave behind stale account identities in the Registry and Credential Manager. These remnants can force a newly installed Office application into an endless authentication loop.
Press Win + R, type 'regedit', and hit Enter. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities and delete the Office account identity folder.
Open the Start menu, search for 'Credential Manager', and select it. Go to 'Windows Credentials', locate your Office 365 account, and click 'Remove'.
Search for 'cmd' in the Start menu, right-click 'Command Prompt', and select 'Run as administrator'.
Type 'cd C:\Program Files\Microsoft Office\Office16' (or C:\Program Files (x86)\Microsoft Office\Office16 if using 32-bit) and press Enter.
Run the command 'cscript OSPP.VBS /dstatus' and note the last five characters of your installed product key displayed in the results.
Run 'cscript OSPP.VBS /unpkey:XXXXX', replacing XXXXX with the five characters you found. You should see a success message. Restart your computer and try signing into Office again.
Use Microsoft Support and Recovery Assistant
Run Microsoft's official diagnostic tool to automatically find and fix activation and sign-in problems.
Switch to WPS Office for a Hassle-Free Experience
If you are tired of dealing with Office 365 activation loops and persistent sign-in errors, WPS Office provides a lightweight, highly compatible, and free alternative. Enjoy powerful document editing without the complicated account authentication hurdles.
- 1. Download the Installer: Visit the official WPS Office website and download the free installation package to your computer.
- 2. Install WPS Office: Run the downloaded setup file and follow the quick on-screen instructions to complete the installation.
- 3. Open Your Office Files: Launch WPS Office and directly open your existing .docx, .xlsx, or .pptx documents without any sign-in barriers.
Frequently Asked Questions
Why does Office 365 keep asking me to sign in after a fresh install?
When you uninstall Office, Windows often retains your old account credentials in the Windows Credential Manager and the system Registry. These stale or corrupted files cause the sign-in loop to persist across new installations.
How do I safely back up my Windows Registry before deleting Office identities?
Press Win + R, type 'regedit', and press Enter to open the Registry Editor. Click on 'File' > 'Export', choose 'All' under Export range, name your backup file, and save it to a safe location like your Desktop.
Will deleting the Office registry key erase my Word or Excel documents?
No. Deleting the Office identity keys in the Registry only clears the cached account login data used by the software. Your personal documents, spreadsheets, and presentations are saved separately and will remain unaffected.
