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。

Scroll up or down to find the symbol you want to insert. Different font sets often have different symbols in them and the most commonly used symbols are in the Segoe UI Symbol font set. Use the Font selector above the symbol list to pick the font you want to browse through.

但如果需要测试多个条件，例如我们假设所有条件都需要为 True 或 False (AND)，或只有一个条件需要为 True 或 False (OR)，或者如果想要检查某个条件是否不 (NOT) 符合你的条件，这时该怎么做呢？这三个函数均可以单独使用，但它们更常见于与 IF 函数成对使用。

若要在 Outlook.com 中获取支持，请单击此处或选择菜单栏上的帮助，然后输入查询。 如果自助服务无法解决问题，请向下滚动到“仍需要帮助？”，然后选择“是”。 若要在 Outlook.com 中联系我们，需要登录。

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Check the Xbox services, games, and apps for any service outages.

Learn how to update Windows to ensure your device operates smoothly and securely with the latest features.

Under Ways to sign in , you have three choices to sign in with Windows Hello:. Select Facial recognition (Windows Hello) to set up facial recognition sign-in with your PC's infrared camera or an external infrared camera

Note: Some cameras won't appear in the Camera settings page.These include infrared (IR) cameras used for Windows Hello Face authentication, cameras using DirectShow technology (like many apps provided by DSLR or action camera manufacturers so their devices can be used as webcams), and proprietary cameras that aren't managed by Windows—such as industrial cameras and many networked cameras.

Learn how to activate Office pre-installed on new Windows 10 PCs or with a new product key.