Difference Between Service Account and User Account
social.technet.microsoft.com › Forums › lyncApr 23, 2014 · Service Account Lockout When the password for a service account is changed, the password must be updated in all locations that use the service account. A user account can become locked after to many wrong password attempts. When the service account is used in multiple locations and the password is not updated in all locations, the old password will still be used. After Windows Server 2003 with Service Pack 1, Active Directory will check the last two passwords used.