If you suspect that someone has hacked your Yahoo! account or if you attempt to log in your account too many times with an incorrect password, Yahoo! might lock you out of your account. After several failed login attempts, the Yahoo! security feature locks your account for a predetermined amount of time to prevent unauthorised users from accessing your account. Unauthorised users might use your account to send unsolicited e-mails or intrude on your private content and e-mails. Although being locked out of your Yahoo! account can be frustrating, you can gain access to your account and change your password after the lock expires.
Wait 24 hours.
Return to the Yahoo! website and click the "Sign In" link at the top of the page.
Click "I Can't Access My Account."
Select "I Forgot My Password" or "My Password Doesn't Work" from the list of options. Click the "Next" button to proceed.
Enter your Yahoo! ID in the "My Yahoo! ID is" field.
Enter the security code in the "Enter the Code Shown" field. Click the "Next" button.
Click "I Cannot Access Any of the Above" and click the "Next" button.
Type the answers to the security questions in the appropriate fields. You set these security quests when you created your Yahoo! Account. Click "Next."
Enter a new password in the field and verify the password by retyping it in the field. Click the "Next" button and Yahoo! resets your password. The new password is effective immediately, allowing you to sign in your Yahoo! account.
Change your password frequently to prevent your account from being hacked.