了解如何使用产品密钥或数字许可证激活 Windows、检查激活状态，以及链接Microsoft 帐户。

Use VLOOKUP, HLOOKUP, and other functions like INDEX and MATCH to search for and find data based on values you enter. This article gives you a quick VLOOKUP refresher, then links to more.

Learn how to recover deleted items, such as email, contacts, calendar appointments, and tasks in Outlook.

An upgrade differs from an update in that it moves your PC from a previous version of Windows—such as Windows 10—to Windows 11. This FAQ is intended to answer questions about upgrading to Windows 11.

Learn how to access Windows device security settings in Windows Security to help protect your device from malicious software.

Learn different ways to locate your BitLocker recovery key in Windows, and learn about how BitLocker might have been activated on your system.

Use your Microsoft account to sign in to Microsoft services like Windows, Microsoft 365, OneDrive, Skype, Outlook, and Xbox Live.

Get more out of your email with Outlook.com. We've streamlined search to make it easier than ever to find what you're looking for. New features like Files and attachment previews let you see your pictures and files without leaving your inbox.

Learn how to open a shared mailbox in Outlook. Shared mailboxes let a group of users view and send email, and share a calender, and open a contact list from a common mailbox.

Get an overview of SharePoint. Learn about sites, lists and libraries, permissions, content types and workflows. In addition, read about some of the social features in SharePoint.