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

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 It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired.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 ...

了解如何在 Android 手机或平板电脑上设置 Xbox Cloud Gaming。 包括安装 Xbox 应用、使用邀请链接以及使用 Game Pass Ultimate 流式传输游戏的步骤。

Important: You don't need to remove old security information unless there is an account security risk (e.g. someone else has access to your old mailbox). If you do need to replace your security information, make sure you add new information first. If you request removal of all security information in your account, the account is put into a restricted state for 30-days. Your information doesn't ...

在 Windows 10/11 玩遊戲時，透過社交網路與朋友保持聯繫。

如果您移至新的國家/地區，在購買之前，請確定您的帳單地址和付款選項符合您的新地區。

Before you can use Authenticator as a way to sign in, you need to download the app and have already added Authenticator to your accounts. Starting July 2025, the autofill feature in Authenticator will stop working, and from August 2025, passwords will no longer be accessible in Authenticator.

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

了解如何將遊戲和應用程式下載到 Xbox，包括如何暫停、變更下載順序或重新安裝。

To learn about digital signatures (also known as digital ID), what they can be used for, and how to them in Word, Excel, and PowerPoint, see All about digital signatures. Create a signature line in Word or Excel In the document or worksheet, place your pointer where you want to create a signature line. On the Insert tab, select Signature Line in the Text group. In the Signature Setup dialog ...