Some Office 2019, Office 2016, and Office 2013 products come with a product key. If yours did, before installing Microsoft 365 for the first time, sign in with an existing or new Microsoft account and enter your product key at office.com/setup. Redeeming your key is what links your account with Microsoft 365 so you only have to do this once.

If some Windows functions aren't working or Windows crashes, use the System File Checker to scan Windows and restore your files. Though the steps below might look complicated at first glance, just follow them in order, step-by-step, and we’ll try to get you back on track. Run the System File Checker tool (SFC.exe)

Download and install or reinstall Microsoft 365 or Office 2021 on a PC or Mac. Set up Office apps and email on a mobile device. Small business help and learning. Learn how to download and install apps you need from your Microsoft 365 business subscription.

Learn how to add user accounts in Windows 10 and Windows 11. With an account, each person has separate files, browser favorites, and a private desktop.

Learn how to redeem a gift card, code, or Office product key and spend your balance at Microsoft Store online, on Windows, or Xbox.

Sign in to SharePoint. SharePoint is a browser-based app that you connect to through your web browser, like so: Go to office.com, and sign in to your work or school account. In the upper left corner of the window, select the app launcher > All apps > SharePoint. Tip: If you don't see the SharePoint app under All apps, use the Search box near ...

Contact Microsoft Support. Find solutions to common problems, or get help from a support agent.

Change from a 32-bit version to a 64-bit version or vice versa. Activate Windows. Fix Bluetooth problems in Windows. Learn how to install, reinstall, or activate Microsoft 365 or Office 2019 on a PC or Mac.

Once the Windows 11 upgrade has been tested and validated for your specific PC, Windows Update will indicate that it's ready for installation. To check if Windows 11 is ready for your device, go to Start > Settings > Update & Security > Windows Update and select Check for updates.

如果Microsoft 365 应用程序（如 Word 或 Excel）无法正常工作，有时重启会解决问题。. 如果这不起作用，你可以尝试修复它。. 完成后，你可能需要重新启动计算机。. Windows 10 Windows 11. 访问修复工具的步骤因操作系统的不同而异。. 右键单击左下角) (“开始” 按钮 ...