Windows 8.1 Update and Windows RT 8.1 Update (also known as KB 2919355) include improvements that make your favorite apps and settings easier to find and use, provide more familiar mouse and keyboard options, and update security and performance.Here’s what you need to know about installing this important update. Check to see if it’s already installed

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提示: 可以使用任何电话号码来请求安全代码。. 电话号码不需要与你的帐户关联。. 手机不需要是智能手机，也不需要连接互联网，只需要能够接收短信。. 你可能需要创建新密码。 阅读有关如何创建强密码的提示。. 如果看到“该 Microsoft 帐户不存在”错误消息，请使用 Microsoft 帐户登录帮助程序。

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注意: 带 USB Type-C 连接器的电脑具有更高的功率限制。 如果连接器支持 USB 电力传输，则其能够以更大的功率实现更快速充电。. 要更快地充电，你的电脑、充电器和线缆均必须符合行业标准。

There are a few common scenarios in which Windows running on a PC might be discovered to be non-genuine during validation. Repairs. If your PC has been repaired, you might start to see messages on your desktop that Windows isn't genuine.

Windows 11 automatically downloads and installs updates to make sure your device is secure and up to date. This means you receive the latest fixes and security updates, helping your device run efficiently and stay protected.

To see where your browser is saving downloads, look in your browser's settings. For example, in the new Microsoft Edge , select Settings and more > Settings > Downloads .The file path for your downloaded files (for example, C:\Users\[your name]\Downloads) is listed under Location.. In Microsoft Edge Legacy , select Settings and more > Settings .

Find Microsoft Excel help and learning resources. Explore how-to articles, guides, training videos, and tips to efficiently use Excel.

Training: Watch and learn how to use PowerPoint in Windows. Explore PowerPoint training guides, articles, and how-to videos.