OS X Mavericks: Solve password problems
If you forget a password, or have trouble keeping track of passwords, try these solutions.
Recover after forgetting a password
If you forget the password you use to log in to your Mac, ask the administrator to reset your login password.
Resetting your password will create a new login keychain. Passwords and other information saved in your previous keychain are not accessible and must reentered.
If you are the administrator (or the only user) of the Mac, or if you encrypted your home folder and you forget that password, see:
If you forget a password for a website, server, or app, see “Use Keychain Access and keychains,” next.
Use Keychain Access and keychains
You can use keychains in OS X to remember passwords for apps, servers, and websites. If an item’s password is stored in a keychain, you can have Keychain Access provide the password when you open the item.
If you have an iCloud account you can use iCloud keychains to store information for web accounts, credit cards, and Wi-Fi networks across your Macs and iOS devices.
About Keychain Access