After signing in to Microsoft Office 365 applications with my corporate email account, I have to sign in again every time I shut down and restart my computer because my session in Office applications is cancelled.

Dear @Mitchell Erin,

I hope you’re having a good day. 

Thank you for providing the details.

Based on your description, I understand that you can successfully sign in to Microsoft 365 applications, but after every Windows restart, Office forgets the sign-in session and prompts you to sign in again. Since the issue is occurring on both your Windows laptop and desktop, but not on your Android device, this may be related to how authentication tokens are being stored or refreshed on Windows, or possibly to a policy change applied by your organization.

To help narrow down the cause, I would recommend the following checks:

1. Check whether "Always keep me signed in" is displayed

The next time Office prompts you to sign in:

• Enter your credentials.
• If prompted with "Stay signed in?" or "Keep me signed in?", select Yes.

Please note whether this prompt appears at all.

2. Check Credential Manager

On both affected PCs:

• Open Control Panel > Credential Manager.
• Select Windows Credentials.
• Look for Microsoft 365, Office, AAD, or Microsoft-related credentials.

Check whether these credentials remain after a reboot or appear to be removed automatically.

3. Confirm whether all Office apps are affected

Could you confirm whether the issue occurs in: Word/Excel/PowerPoint/Outlook... or only certain Office applications?

4. Verify Windows work account connection

Go to: Settings > Accounts > Access work or school

Please confirm:

• Is your university account listed there?
• Does it show as connected without errors?

5. Test Office in Safe Mode

Sometimes an add-in or local profile issue can affect authentication.

For example, to start Excel in Safe Mode: Press Win + R > Excel /safe

Sign in and test whether the sign-in persists after restarting the computer.

6. Ask your university IT department whether any authentication policies changed recently

Since the issue started only 2-3 weeks ago and affects multiple Windows devices, it would be worth asking whether the university recently implemented changes such as:

• Conditional Access policies
• Sign-in frequency policies
• New Microsoft 365 security controls
• Device compliance requirements

Those changes can sometimes affect how often users are prompted to authenticate.

I hope these steps help narrow down the cause. Please let me know the results, especially what you find in Credential Manager and Access work or school, and I'll be happy to suggest the next troubleshooting steps.

Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.   

Looking forward to hearing back from you with any updates or additional details.  

Warm regards,  

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