了解在 Windows 中查找 BitLocker 恢复密钥的不同方法，并了解如何在系统上激活 BitLocker。

If your purchase of Office or Microsoft 365 came with a product key, you enter your product key on one of the websites listed below for your product.

If you get an email about unusual activity on your Microsoft account, or if you’re worried that someone else might have used your account, go to the Recent activity page.You’ll see when your Microsoft account was signed in during the last 30 days, along with any device or app-specific info.

Create an alias to give you an additional email address which uses the same inbox, contact list, and account settings as your primary email address in Outlook.com.

Learn how to troubleshoot Windows activation errors. Browse common activation errors and learn what you can do to fix them.

Learn how to fix problems signing into your Microsoft account. Resolve password verification, locked account, and other Microsoft account login issues.

Learn how to restore files that have been permanently deleted and are no longer in the recycle bin on Windows 10.

Learn how to recover deleted items, such as email, contacts, calendar appointments, and tasks in Outlook.

Learn how the Photos app for Windows lets you view photos and videos from your PC alongside those from OneDrive, and keeps them organized by date, album, or folder.

View your Outlook email messages arranged by conversations to see messages that share the subject line grouped together.