Learn how to access Windows device security settings in Windows Security to help protect your device from malicious software.

Learn how to restore files that have been permanently deleted and are no longer in the recycle bin on Windows 10.

Learn how to find a Windows product key for activation, and when you'll use a digital license instead.

了解如何使用产品密钥或数字许可证激活 Windows、检查激活状态，以及链接Microsoft 帐户。

Tell us your problem so we can get you the right help and support.

Follow the steps in this article to help you cancel your Microsoft 365 subscription.

These steps are the same whether you're adding your first iCloud email account or additional iCloud accounts to Outlook. Select a tab option below for the version of Outlook you're using.

Learn how to access the Control Panel in Windows for managing your system settings and programs.

Show the ribbon when hidden, and set options to shows tabs and commands, just tabs, or automatically hide the ribbon for the maximum document space.

If your computer is showing a black or blank screen in Windows, these troubleshooting tips could help get your system back up and running.