Learn how to encrypt an email message in Outlook using Microsoft 365 Message Encryption or S/MIME encryption. Choose the encryption option that suits your needs and follow the instructions for your Outlook version.

Learn how to protect your security and privacy by blocking or unblocking external content, such as images, media, hyperlinks, and data connections, in Office files. See how to change settings for data connections, workbook links, and linked data types in Excel.

Learn how to avoid and remove ransomware, a malware that encrypts your files or stops you from using your computer until you pay money. Find out how to update Windows, turn on security features, store files on OneDrive, and more.

Learn how to switch to the new Outlook for Windows, a preview app with the latest features and design. Find out how to import settings, customize the experience, and get feedback or support.

Learn how to change meeting options for security, efficiency, and engagement in Teams. Find out how to set sensitivity labels, lobby, co-organizers, presenters, chat, recording, and more.

Learn how to read and reply to encrypted messages in Outlook for Windows with Microsoft 365 or other mail services. Find out how to send encrypted messages, use digital signatures, and get a digital ID.

Learn how to send and read encrypted messages in Outlook.com with Microsoft 365 subscription. Choose from Encrypt or Do Not Forward options to protect your confidential and personal information.

Learn how to create and use app passwords for devices that don't support two-step verification. Find out how to sign in with app passwords for Xbox 360, Outlook, BlackBerry, and more.

如果这是你第一次安装 Microsoft 365，则可能需要先执行一些设置步骤。展开下面的 “了解详细信息”部分。 但是如果是重新安装 Microsoft 365，且已兑换了产品密钥并拥有与 Microsoft 365 相关联的帐户，请转到“登录并安装 Office”的部分。

Find out how to use OneDrive to store, share, sync, and protect your files and photos. Get tips, troubleshooting, and FAQs for OneDrive on PC, Mac, mobile, and web.