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 It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired.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

Find out how to submit a request for a refund for a purchase of digital Xbox content.

Learn how to use mobile operator billing as a payment option to buy Xbox subscriptions, games, and other content.

This security update includes fixes and quality improvements that are part of the following updates: October 14, 2025—KB 5066791 (OS Builds 19044.6456 and 19045.6456) November 11, 2025—KB5071959: Windows 10, version 22H2 (OS Build 19045.6466) Out-of-band The following is a summary of the issues that this update addresses when you install this update. If there are new features, it lists ...

How to manage Kerberos KDC usage of RC4 for service account ticket issuance changes related to CVE-2026-20833

Find everything you need to manage your Microsoft account, Xbox profile, and more.

Notes: If you don't see the security key option, it's possible that your organization doesn't allow you to use this option for verification. In this case, you'll need to choose another method or contact your organization's help desk for more assistance. Before you can register a security key, you must have at least one additional security verification method registered.

If you're trying to buy a game or an add-on using your Microsoft account balance, you may not have enough funds in your account to cover the total cost of the item. For example, if you try to buy a game that's listed as $9.99, and you have a Microsoft account balance of $10.00, that amount wouldn’t be enough to cover the taxes, so you'd need to add more funds pay the total balance.

How to add a signature to your Word documents. You can also use the Signature Line command in Word to insert a line to show where to sign a document.

NOTE Improved diagnostics have been added to detect and report issue details through the event log. Please see KB5016061: Addressing vulnerable and revoked Boot Managers for more information.