How to create or edit your Outlook signature for email messages. Include your signature, text, images, electronic business card, and logo.

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

Learn what to do if you see error 0x803F9006 when you start a game or app on your Xbox console.

Learn how to use the Gaming Services Repair Tool to troubleshoot installation and update issues with Gaming Services on PC.

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 It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired.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

If you see error 0x803f8001, check the Xbox service status. Find more solutions here.

You can resolve problems with Microsoft Authenticator by checking the tips in this article and reviewing some of the known errors.

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

Learn what to do when you get error 0x82D40003 so you can launch a game on your Xbox console.

Learn how you can use the free Microsoft Authenticator app to sign in to all your accounts without using a password.