Learn how to use Microsoft Defender Antivirus to scan and remove malware from your PC. Follow the steps to run an offline scan, view the results, and restore your system.

Learn different ways to remove apps and programs from your Windows 10 or 11 device. Find tips for troubleshooting, repairing, and protecting your system from malware.

Learn how to find, add, turn off, and remove extensions in Microsoft Edge, the browser for Windows 11 and Windows 10. Extensions are tools that customize your browser experience and offer you more control.

Learn how to redeem a Microsoft gift card, Xbox download code or token, Office product key, or Windows activation code to your Microsoft account. Find troubleshooting tips and contact support if you need help.

Learn how to use the PC Health Check app or the Microsoft Compatibility Appraiser task to see if your device meets the system requirements for Windows 11 after changing your hardware. Find out how to refresh the eligibility assessment and what factors affect the upgrade offer.

Learn how to download and install Microsoft 365 apps, like Word, Excel, and PowerPoint, on your PC or Mac. Follow the instructions in the browser and sign in with your Microsoft 365 account to activate the apps.

Learn how to view and delete your Microsoft Edge browsing history stored on your device, across synced devices, and in the cloud. You can also clear Internet Explorer browsing data using Microsoft Edge if your organization has turned on Internet Explorer mode.

Learn how to use VLOOKUP, HLOOKUP, INDEX and MATCH to look up values in Excel tables. See examples, tips and limitations of each function, and how to use the new XLOOKUP and XMATCH functions.

如果这是你第一次安装 Microsoft 365，则可能需要先执行一些设置步骤。展开下面的 “了解详细信息”部分。 但是如果是重新安装 Microsoft 365，且已兑换了产品密钥并拥有与 Microsoft 365 相关联的帐户，请转到“登录并安装 Office”的部分。

Compare the differences between Microsoft 365 subscription and Office 2021 one-time purchase. Learn about the benefits of cloud storage, security updates, and technical support for Microsoft 365, and the fixed versions and no upgrades for Office 2021.