Get started with Microsoft Teams (free). Explore your options, find out what’s new, browse help topics, and more.

激活有助于验证你的 Windows 副本是否为正版，且未在超过 Microsoft 软件许可条款所允许数量的设备上使用。 本文将帮助你找出并改正 Windows 中常见的激活错误。

Learn about the quotas and differences between Microsoft storage and email storage.

如果知道用户名和密码但已停止工作，请阅读 我的用户名和密码已停止工作。. 如果你忘记了 Microsoft 帐户用户名或电子邮件地址， 并且 之前已在 Microsoft 帐户上设置了其他 安全信息 ，请按照以下步骤操作。

The new Microsoft Edge helps you browse, search, shop online, and more. Like all modern browsers, Microsoft Edge lets you collect and store specific data on your device, like cookies, and lets you send information to us, like browsing history, to make the experience as rich, fast, and personal as possible.

Hotmail 現在為 Outlook.com。 瞭解如何登入以存取您的 Outlook.com、Hotmail、Live 或 MSN 電子郵件帳戶。

How to use the SUMPRODUCT function in Excel, one of Excel’s math and trig functions, using multiplication, addition, subtraction, and/or division to return the sum of the products of corresponding ranges or arrays.

Discusses the release of the Malicious Software Removal Tool (MSRT) to help remove specific prevalent malicious software from Windows-based computers.

你可以随时取消 Xbox 订阅。 关闭定期计费将停止订阅的未来扣费，并使你在订阅到期之前使用其权益。 你也可能有资格立即取消并获得退款；但不是所有订阅费用都能退款。

从确保设备可以运行 Windows 11 到备份文件和安装 Windows 11，了解如何为 Windows 11 升级做好准备。