Hello,

You can change the behavior of the password input field in the following fie, if you are using the password without validation:

CMSModules\Membership\FormControls\Passwords\Password.ascx.cs

For the control used in the form control with validation you need to alter the file:

CMSModules\Membership\FormControls\Passwords\PasswordConfirmator.ascx.cs

You can check for example the following file to see, how to preserve the value:

CMSFormControls/Inputs/LargeTextArea.ascx

For more information about pre-populating BizForms you can also check this knowledge base article.

Best regards,
Boris Pocatko