To remove the ability for users to save their passwords execute the following code in the On Startup Method of your database.

$xml:=DOM Parse XML source($path) DOM SET XML ATTRIBUTE($xml;"md5_password";"") DOM EXPORT TO FILE($xml;$path)

Where the variable $path is the path to the .4DLink file.

Please note that this will not remove the check box. Users can still select the check box; however, the passwords will not be saved.