If there was an unusual sign-in attempt for your account, you'll get an email or text message. We'll send a message to all your alternate contact methods.

Learn how to set your time zone, language, and the date and time format settings in Outlook on the web and new Outlook.

Learn how to change Internet Explorer settings, or reset browser settings when there's a problem.

Learn how to use InPrivate browsing in Microsoft Edge if you don't want your browsing data saved on your PC.

Learn how to open a shared mailbox in the Outlook Web App. Shared mailboxes let a group of users view and send email, and share a calendar, from a common mailbox.

Describes how to troubleshoot problems that occur when you install, uninstall, or upgrade a program on a Windows-based computer by using Windows Installer.

Need to uninstall Office for Mac? It's quick and easy. Just follow these simple steps.

With Excel for the web running in your web browser, you can: Share your workbook with others and collaborate on the same file at the same time.

即使已开启其他防火墙，开启 Microsoft Defender 防火墙也很重要。 它保护你免遭未经授权的访问。 若要打开或关闭 Microsoft Defender 防火墙，请执行以下操作：

Learn how to remove passwords from your Microsoft account to increase security.