If you've recently changed your network password, you may begin receiving "Keychain Access wants to use the 'Login' keychain..." dialog boxes frequently while using your Mac:
This is typically caused when changing your password via the webmail interface, as opposed to the sanctioned method outlined here, (but can happen in other ways, as well), and will continue to happen until the password for your "login" Keychain matches your newly-chosen network password.
The quick way to stop these pop-ups is to enter your most recent previous password; chances are, they keychain is tied to that password and wants that password to unlock the keychain. But this is only a temporary fix, and the pop-ups will come back the next time you restart your computer. There are two ways to stop these pop-ups for good. The first is to try to update your Keychain Password (which will retain your keychain, and all passwords you have saved), the second is to reset your keychain (removing all saved passwords from your machine).
Upadte Keychain Password
1. First, navigate to your Utilities folder on your Mac (which is in the Applications folder), and open the Keychain Access application. You can also do a Spotlight search for "keychain access" and you can open the application that way.
2. Next, in the menu bar at the top of the screen, choose Edit > Change Password for Keychain "login"...
3. Under Current Password, enter your most recent previously used password, and under New Password and Verify, enter your current login password, then click OK. If you enter the wrong current password, don't worry: keep trying previous passwords until it accepts it.
If you cannot figure out which password it likes for Current Password, proceed to the Reset Keychain option below.
1. Navigate to the Self Service application in your Applications folder. Log in using your first.last user name and your IPG password.
2. On the main page, under Featured, click the Reset button for the Reset Keychain option.
3. This will force a restart of your computer. When you log back in after restart, your computer will have forgotten any previously saved passwords (Outlook, OneConnect wireless, AOL instant messenger, Facebook, etc.), so you will have to rebuild your new keychain by clicking the "save this password" option as you log in to these things.