Learn how to unlock your Microsoft account and resolve 'account has been locked' error message.

Learn how to personalize a Windows lock screen with a background photo, slideshow, or app notifications.

How to lock cells in Excel to protect your data. You can also unlock a range of cells and grant permissions to others to edit.

Learn how to find your BitLocker recovery key in Windows.

Go to File > Info > Protect Document > Encrypt with Password. Type a password, press OK, type it again and press OK to confirm it. Save the file to make sure the password takes effect.

Discover the step-by-step process to change or reset your Windows password if you've lost or forgotten it. This guide will help you regain access to your Windows account quickly and securely.

Learn how to sign in, sign out, lock, and switch user account in Windows.

Use Find my device to locate and lock your lost or stolen Windows devices.

Learn about BitLocker Drive Encryption in Windows and how to encrypt drives.

To lock your file so that other users can't open it, see Protect an Excel file. To protect certain areas of the data in your worksheet from other users, you have to protect your worksheet.

Restrict permission to content in a file. You can add a password to an Excel file to prevent unauthorized users from opening or modifying it.