If the account policy User must log on in order to change password is checked in Windows NT 3.5, 3.51, or 4.0, Network Client for MS-DOS 3.0 clients are unable to change their passwords. The policy is meant to keep users with expired accounts from being able to change their passwords. However, these clients receive Access Denied errors when they attempt to change their passwords, regardless of their account status.
This problem occurs because Network Client sets an inappropriate flag when it requests a password change on a Windows NT Server.
To work around this problem, turn off the User must log on in order to change password policy in User Manager on the computer running Windows NT Server.