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

如果我的代码来自其他区域，该怎么办？ 某些数字代码适用于可能与帐户上的区域设置不匹配的特定国家/地区。 如果你的帐户与你的物理区域匹配，并且你的代码是从你所在地区的零售商处购买的，请确保设备上的区域也与你的物理位置匹配。 若要从 Xbox 主机执行此作，请执行以下作：

See how to view the details for signatures and certificates.

Contact Microsoft Support. Find solutions to common problems, or get help from a support agent.

Certificate authority (CA) A certificate authority is an entity similar to a notary public. It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired. Top of Page Digital signature assurances The following terms and definitions show what assurances are provided by digital signatures. Authenticity The signer is ...

Here are the most likely causes for an unrecognized charge: A Microsoft subscription has recurring billing enabled. Someone you know, such as a family member, bought something with your card. You can now investigate this on the Manage your payments page. A previously declined charge was charged again. A pre-order or split order was shipped. Someone made an in-app purchase from an app, game, or ...

瞭解如何透過瀏覽器、Xbox 主機或 Windows 裝置變更您的 Xbox 玩家代號。

This page provides support links for home users and support phone numbers for business users.

Learn how to manage your Microsoft account security info and troubleshoot verification code issues.

Learn how to use encryption and other security settings to protect messages sent from Outlook.