To sign in to your work or school account, go to myaccount.microsoft.com or select Sign in below. Use your Microsoft account to sign in to Microsoft services like Windows, Microsoft 365, OneDrive, Skype, Outlook, and Xbox Live.

注意 註解 為了正確驗證由可信簽署（Trusted Signing）簽署的模組，電腦必須安裝「Microsoft Identity Verification Root Certificate Authority 2020」憑證授權機構 (CA) 。 預設情況下，只要電腦連接網際網路，根憑證會自動安裝。

Use our Sign-in Helper for quick assistance: If you’re having trouble signing in to your Xbox account, Sign-in Helper is the fastest way to get signed in. It will ask you for your email address or phone number, check your account for any problems, and tell you what you need to do to sign in.

Find solutions you can try to fix error 0x87e5000a so that you can get back to your game.

Microsoft and Windows components are signed by leaf certificates mainly issued by six Microsoft Issuing CAs. Beginning in July 2025, these 15-year Issuing CAs begin to expire according to the following schedule.

Sign-in to Product Activation Portal To access the Product Activation Portal, a human operator must complete a CAPTCHA and authenticate with a supported account type.

If you can't sign into your Microsoft account, most issues can be identified by our sign-in helper tool. The tool will ask you to enter the email address or mobile phone number you're trying to sign in with and check the details you provide.

Sign in to your Advanced security options on your Microsoft account security dashboard. Scroll down to Sign out everywhere and select Sign out. Signing out may take up to 24 hours. Avoid staying signed in on a public computer. Manage devices used with your Microsoft account.

Your account becomes accessible to all desktop and web applications that use your work or school account for sign-in. In many cases, these applications automatically use your work or school account without requiring any interaction, so you don't need to enter your credentials when you open them.

Fix authentication issues in Office applications when you try to connect to a Microsoft 365 service.