Use the Microsoft 365 network connectivity test to measure connectivity between your device and the internet, and from there to Microsoft’s network. Use the MIcrosoft 365 inventory scan troubleshooter to generate either a normal online Outlook email repair utility or full scan report of your computer and installed Microsoft 365 applications. Use the Microsoft 365 sign-in troubleshooter to help resolve sign-in issues encountered with Microsoft 365. If you can't sign into your Microsoft account, most issues can be identified by our sign-in helper tool.

How do I fix the ‘Product Activation Failed’ error in Microsoft 365?

Additionally, ensure you’ve installed all available updates, as performance improvements are often included in patches. Regularly cleaning up your hard drive or upgrading hardware like RAM can also enhance performance. If you’ve tried all these steps and still can’t resolve the sign-in or activation errors, you may need more advanced troubleshooting. Completing the above steps resolves a large majority of Exchange connectivity diagnostic typical sign-in and activation problems.

Recover your account

Office 365 uses several internet endpoints and cloud services to authenticate users and validate licenses. If these connections are disrupted, sign-in and activation will fail. Use the Excel check troubleshooter to resolve Excel for Windows startup, hang, or crash issues. Get Help has troubleshooters for Microsoft 365 you can run for many common scenarios. These often help resolve issues without the need to contact support. If a troubleshooter is available for your issue, select Start to run that troubleshooter.

3 Step 3: Verify Network Connectivity and Firewall Settings

• Yes, Microsoft 365 works offline for most apps like Word and Excel.
• If syncing is paused, resume it from the OneDrive system tray icon.
• In these scenarios, you’ll need more in-depth knowledge of Office 365 licensing, Azure Active Directory (Azure AD) configurations, or advanced policy settings.
• Other times, it might be network problems, conflicting versions of Office, or organizational security policies that block the authentication process.
• Look up the error code on the official Microsoft site for tailored steps.

You might find it simple, but the most common cause of login failure is entering the wrong username and password combinations. Below is a structured approach to diagnosing and resolving Office 365 sign-in or activation errors. Start with the basics and move toward more advanced methods only if necessary.

Microsoft 365 Troubleshooting – Quick Fixes for Common Problems

Look up the error code on the official Microsoft site for tailored steps. FixTechGuide Outlook repair tutorial Check if your system meets the Microsoft 365 installation prerequisites. For codes linked to storage limitations, free up disk space or install on an external drive.