Learn how to use the System File Checker tool (SFC.exe) to scan and restore missing or corrupted system files in Windows. Follow the steps to run the tool, view the details, and manually replace the corrupted files if needed.

Learn how to download and install Microsoft 365 or Office 2019, 2016, or 2013 on your PC or Mac. Find out how to activate Office, troubleshoot issues, and switch languages or bit versions.

Learn how to access SharePoint, a browser-based app for online collaboration and document management, through your web browser. Find out how to check your subscription, troubleshoot issues, and get training for SharePoint.

Learn how to use a scanner and the Windows Scan app to save files to your PC. Find out how to install and use a scanner in Windows 11 or Windows 10.

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, phone, or email options.

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.

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 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.

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.

Learn how to fix errors while downloading and installing Windows updates using the Update Troubleshooter. Follow the steps to run the troubleshooter, restart your device, and check for new updates.