How to remove white border from right and down part instead having BorderStyle := bsNone in Inno Setup?

Question

I have been trying making a border-less movable Inno Setup and figured how to make it movable and border-less but there are still border at the right and down part.

First my code was BorderStyle := bsDialog.

I changed to BorderStyle := bsNone to make the setup border-less.

Answer 1

Remember a client size of the window before you change the BorderStyle and restore the client size afterwards:

procedure InitializeWizard();
var
  ClientWidth: Integer;
  ClientHeight: Integer;
begin
  ClientWidth := WizardForm.ClientWidth;
  ClientHeight := WizardForm.ClientHeight;

  WizardForm.BorderStyle := bsNone;

  WizardForm.ClientWidth := ClientWidth;
  WizardForm.ClientHeight := ClientHeight;
end;