Q: Retrieving forgotteb IMAC password

Hi there DorisS,

If I understand correctly you are trying to install printer driver but when you get propted for the Admin password, you dont know it so cannot continue. You may be able to reset that password with the following article:

OS X: Changing or resetting an account password

In OS X Lion or later, you can reset your user password with your Apple ID. If you have not linked your Apple ID to your OS X user account, use the steps below to reset your password instead.

Important: Passwords for administrator accounts should not be blank. When you perform these steps, make sure you enter a new password as part of these steps.

 

1. Log in with an administrator account. 
2. From the Apple menu choose System Preferences.
3. From the View menu choose Users & Groups.
4. Click the lock button if it appears locked; enter the administrator password.
5. Select the name of the user whose password you want to change.
6. Click the Reset Password button or the Change Password button.
7. Enter a new password in both the New Password and Verify fields, and add a Password Hint if desired.
8. Click the Reset Password button or the Change Password button.