About digital signatures and certificates in Office, and buying a digital certificate from a certificate authority or create your own.

Xbox Support offers help for Xbox, Game Pass, and billing questions. Get advice and customer service in the Xbox Support community.

Microsoft Authenticator helps you sign in to your accounts if you've forgotten your password, use two-step verification or multi-factor authentication, or have gone passwordless on your account.

MICROSOFT SUPPORT The Microsoft Authenticator app helps you sign into your accounts when you're using two-step verification.

Related articles Contact support and provide feedback in new Outlook for Windows Get in-app help for Outlook for iOS and Android

准备好安装 Microsoft 365 或 Office 2024 了吗？ 在开始之前，请确保电脑或 Mac 满足 系统要求。 如果已兑换产品密钥、重新安装应用，或者已通过工作或学校分配了许可证，则可以跳到登录部分 ，下载并安装 Microsoft 365 或 Office。 但是，如果是 首次 安装 Microsoft 365 或 Office，可能需要先执行一些步骤 ...

A phishing email is an email that appears legitimate but is actually an attempt to get your personal information or steal your money. Some deceptive emails appear to be from a safe sender but, in fact, have a "spoofed" source address to fool you. Here are some ways to deal with phishing and spoofing scams in Outlook.com. Spoof intelligence in Exchange Online Protection helps prevent phishing ...

Learn how to download and install apps you need from your Microsoft 365 business subscription.

重要: 对 Office 2016 和 Office 2019 的支持已于 2025 年 10 月 14 日终止，并且不会有扩展安全更新。 所有 Office 2016 和 Office 2019 应用将继续正常运行。 但是，你可能将自己暴露在严重并且可能有害的安全风险之下。

Learn how to activate Office that is pre-installed on new Windows 10 PCs or using a new product key.