How to fix error 2604? "No network connection" When I try to sign in to Microsoft 365 Business apps from Windows 11 Home

Hi Maik,

This issue is not actually caused by your internet connection, but by the device-level sign-in process. When you select “Yes”, Windows attempts to register your business account with the device (at the system level), which can fail on Windows 11 Home using a local account and results in the misleading error [2604].

You can try the following steps to resolve this issue:

Option 1: Use “This app only”

When prompted, please select “No, sign in to this app only”

This will help avoid device registration.

Option 2: Add your work or school account to your device

In the Windows search bar, search for "Access Work or School".   

Check if you can see your school account in "Access Work or School".   

If you don't see it, please select Connect and add your business account.   

If you can see it connect to the wrong account, please select it and select Disconnect. After that, please click "Connect" and log into your account again to register the device.   

This step registers your account with your organization’s authentication services. Once completed, your device can seamlessly use your organization credentials for apps that require sign-in, so you won’t need to manually enter them each time. As part of this process, your organization may also be able to view basic device information, such as the machine name and operating system.

Option 3:

If option 2 doesn't help, you will have to clear your credentials cache to ensure a clean reset on your device.

Please perform Option 2 first, then process with the following steps:

• Open the Control Panel on your PC.   
• Go to User Accounts > Credential Manager.   
• Under both Windows Credentials and Generic Credentials, look for any entries related to your Microsoft 365 business account and Office apps.   

• Select and remove those entries.   
• Restart your computer and try adding your account in Office again.  

Download OLicenseCleanup.vbs and run it. In this way, you can use this package to remove the license, clear the stored identities in the registry, and remove the credentials. You can follow this: Reset activation state for Microsoft 365 Apps for enterprise - Microsoft 365 Apps | Microsoft Learn to reset activation state 

Restart your device.

Reopen Office apps and sign in with the correct account.

• Open the Control Panel on your PC.   
• Go to User Accounts > Credential Manager.   
• Under both Windows Credentials and Generic Credentials, look for any entries related to your Microsoft 365 business account and Office apps.   

• Select and remove those entries.   
• Restart your computer and try adding your account in Office again.  

Download OLicenseCleanup.vbs and run it. In this way, you can use this package to remove the license, clear the stored identities in the registry, and remove the credentials. You can follow this: Reset activation state for Microsoft 365 Apps for enterprise - Microsoft 365 Apps | Microsoft Learn to reset activation state 

Restart your device.

Reopen Office apps and sign in with the correct account.

If the issue persists, please reach out to your IT admin and ask them to verify:

• Is device registration required?
• Are there Conditional Access policies blocking unmanaged devices and personal/local devices?

For more information, please consult: Add Your Work or School Account to a Windows Device - Microsoft Support

I hope this provides enough clarity and helps you stay inform with your current situation.

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Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.   

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