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.

However, if you're reinstalling Microsoft 365, and you've already redeemed a product key and have an account associated with Microsoft 365, then go to the section sign in to download Office.

If you recently made any changes to your hardware and want to see if your computer now meets the requirements for Windows 11, the easiest way to do that is with the PC Health Check app: If you haven't yet, install the PC Health Check app here.

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.

If you get an error code while downloading and installing Windows updates, the Update Troubleshooter can help resolve the problem. Select Start > Settings > System > Troubleshoot > Other troubleshooters. Next, under Most frequent, select Windows Update > Run.

If you're looking for Help on specific Excel Add-ins, such as Solver or Inquire, see Help for Excel for Windows add-ins. If you're looking for additional help with Excel add-ins using the COM Add-ins dialog box, see Add or remove add-ins in Excel. Get a Microsoft 365 Add-in for Excel.

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.

下载并安装或重新安装 Office 2019、Office 2016 或 Office 2013. 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 ...

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