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

Learn how to download and install Microsoft 365 apps, like Excel, 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 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 view, install, and change settings for add-ins that enhance Microsoft 365 programs. Find out how to deal with add-in crashes, device permissions, and subscription cancellations.

Learn how to add, remove, connect, and disconnect user accounts in Windows 10 and Windows 11. User accounts let each person have their own settings, documents, and applications, and can help with security and privacy.

Find solutions to common problems, or get help from a support agent for Microsoft 365, Office, Windows, Xbox, Surface, and more. Sign in to get personalized help and access live chat with a Microsoft specialist.

Microsoft 365 is a subscription service that offers the latest productivity tools, cloud storage, and support, while Office 2021 is a one-time purchase that does not include upgrades or updates. Compare the features, prices, and benefits of both options and find out which one suits your needs.

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。

Learn how to download and install Microsoft 365 or Office 2021 on your device, whether you have a Microsoft account, a work or school account, or a product key. Find out how to activate the apps, change the version, and get help with common issues.

Learn how to switch to the new Outlook for Windows, a preview app with the latest features and design. Find out how to import settings, customize the experience, and manage your email and calendars.