Stay protected with Windows Security - Microsoft Support
Learn how to use antivirus protection in Windows Security to protect your Windows PC against malware, viruses, and other threats.
Windows sign-in options and account protection - Microsoft Support
Learn how to access and manage your Windows sign in options. Use a password, Windows Hello, or a security key to unlock your device.
在 Excel 中将 IF 与 AND、OR 和 NOT 函数配合使用 - Microsoft 支持
如何将 IF 函数 (与 Excel 中) AND、OR 和 NOT 函数结合使用，以在给定值之间进行逻辑比较。
Applies To:
Excel for Microsoft 365, Excel for Microsoft 365 for Mac, Excel for the web, Excel 2021, Excel 2021 for Mac, Excel 2019, Excel 2019 for Mac, Excel 2016, Excel Web App, Excel for Windows Phone 10
Deinstallieren oder Entfernen von Apps und Programmen in Windows ...
Deinstallieren oder entfernen Sie Apps und Programme in der Einstellungs-App.
激活 Windows - Microsoft 支持
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。
Windows Update Troubleshooter - Microsoft Support
Learn how to run Windows Update Troubleshooter to resolve errors downloading or installing Windows updates.
KB4023057: Update Health Tools—Windows Update Service components
Summary. Microsoft Update Health Tools is offered to devices through Windows Update as update KB4023057. This update is applicable for both Windows consumer and commercial devices, with a slightly different purpose and functionality.
Reinstall Windows - Microsoft Support
Learn how to reinstall Windows on your PC and how activation works after it's installed.
Getting the most out of your PC backup - Microsoft Support
Learn why it's important to have a backup, and how Windows Backup can help you keep your files and settings safe.
Get help with Windows activation errors - Microsoft Support
Learn how to troubleshoot Windows activation errors. Browse common activation errors and learn what you can do to fix them.