Double-check your internet connection, as OneDrive requires an active network to sync files properly. For a larger cache of files, clear up local Outlook OST vs PST repair storage to ensure uninterrupted access. Open apps in Safe Mode to bypass add-ins and check for improvements. Perform a quick repair via "Programs and Features" to optimize performance.

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

By verifying the basics—correct credentials, valid license assignments, and stable network access—you’ll often fix the issue without delving into more complex solutions. Clearing cached credentials, running a repair, or using the Microsoft Support and Recovery Assistant (SaRA) can also address common local device issues. Verify that you’re logged into connection status shows disconnected the correct Microsoft account both in OneDrive and Office apps. If syncing is paused, resume it from the OneDrive system tray icon.

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

• Microsoft 365 is a vital tool for many businesses, and login issues can significantly disrupt day-to-day operations.
• Sometimes, an expired license or outdated credentials are the culprit.
• If we detect a problem with your account, we'll tell you what you need to do to solve the problem.
• Close unused tabs, background processes, or applications to free up system resources.
• Locked accounts, due to multiple failed attempts, may require waiting or following unlock instructions.
• Online guides from Microsoft provide extra steps to speed up slow applications.
• Perform a quick repair via "Programs and Features" to optimize performance.

For manual uninstallation, delete leftover Office files in Program Files or Library folders, and clear Microsoft credentials from your system to ensure a clean reinstall if required. If your account is compromised or hacked, use Microsoft’s sign-in helper to recover your account and reset your security settings. If you are unable to do this and have exhausted all the other fixes, then contact Microsoft Support for professional account recovery. Microsoft 365 is a vital tool for many businesses, and login issues can significantly disrupt day-to-day operations. In this guide, we will take an in-depth look at troubleshooting and resolving common Microsoft 365 login problems so you can keep your business running smoothly. If you’re confident your credentials are correct and the sign-in still fails, proceed to the next step for deeper inspection of license status and subscription details.

Microsoft 365 Troubleshooting – Quick Fixes for Common Problems

Understanding these root causes will help you map out a clearer resolution path. In many cases, performing simple checks—like verifying correct usernames and valid licensing—will resolve the issue quickly. After you run any troubleshooter, Get Help provides details on any findings and suggestions for possible remedies. FixTechGuide support for Office 365 If one of these resolves your problem, close the app and continue working. Use the Microsoft 365 shared computer activation (SCA) troubleshooter to enable shared computer activation for Microsoft 365 applications.