The "Remember my password" checkbox is a IE browser feature and not controlled by a SiteMinder Authentication Scheme or ACO setting. It is controlled via a client side Windows registry edit.
IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to create back up of the registry and ensure that you understand how to restore the registry if a problem may occur. For more information about how to back up, restore, and edit the registry, please review the relevant Microsoft Knowledge Base articles on support.microsoft.com.
In order to disable the checkbox, you need to create/edit this registry key:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings]Value Name: DisablePasswordCachingData Type: REG_DWORD (DWORD Value)Value Data: (0 = default, 1 = disable password cache)
A value of 1 would remove the checkbox from the basic auth prompt. For more information please refer to this Microsoft KB:
As this is a client side update, it would have to be done on each individuals PC. In a corporate environment, this can be push out globally using a Group Policy startup script. First you would create a batch file that makes the required change and then you would call this batch file from within the startup script.
Always make a back up of your registry and test before applying updates.