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

Establishing internet boundaries is an important way to protect yourself and your family from inappropriate web content. Microsoft Family Safety web and search filters work across any Windows, Xbox and mobile device that has the Microsoft Edge browser and Family Safety apps installed.

Connect with friends, family, and coworkers in Teams. Stay organized and connected with friends, family, and coworkers all from one app. Get started

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

Important: You don't need to remove old security information unless there is an account security risk (e.g. someone else has access to your old mailbox).

Press and hold (or right-click) the MP4 file you want to play, select Open with, and then choose your preferred file player from the list of applications.

在“设备”设置中，选择“通过蓝牙发送或接收文件”。

Microsoft generally releases the MSRT on a monthly cadence as part of Windows Update or as a standalone tool. (For exceptions, see Skipped releases.)Use this tool to find and remove specific prevalent threats and reverse the changes that they made (see Covered malware families).For comprehensive malware detection and removal, consider using Windows Defender Offline or Microsoft Safety Scanner.

New to Xbox gaming on PC? Here's how to get started.

Manually download a language for Cortana speech. Go back to Settings > Time & language > Language, select your new language, and then use the up-arrow button to move it to the top of the list and make it the default.