TShowBigDialoxBoxThread=class(TThread)
    private
      FMsg: String;
      FDlgType: TMsgDlgType;
      FButtons: TMsgDlgButtons;
      FHelpContext: Integer;
      FDefaultButton: TMsgDlgBtn;
      FDlgMinWidth: Integer;
      DoShowBigMessageDialog: Boolean;
      function ThreadNotTerminated: Boolean;
    protected
      procedure Execute; Override;
      procedure _ShowBigMessageDialog;
    public
      procedure ShowBigMessageDialog(const Msg: string; DlgType: TMsgDlgType; Buttons: TMsgDlgButtons; HelpContext: Integer;
      DefaultButton: TMsgDlgBtn; DlgMinWidth: Integer);
      constructor Create(CreateSuspended: Boolean = False);
  end;

// ======================================================================================================================
// TShowBigDialoxBoxThread
// ======================================================================================================================

constructor TShowBigDialoxBoxThread.Create(CreateSuspended: Boolean);
begin
  inherited Create(CreateSuspended);
  DoShowBigMessageDialog:=False;
end;

function TShowBigDialoxBoxThread.ThreadNotTerminated: Boolean;
begin
  try
    Result:=not(Terminated or Application.Terminated)
  except
    Result:=True;
  end;
end;

procedure TShowBigDialoxBoxThread.Execute;
begin
  while ThreadNotTerminated do begin
    Sleep(100);
    if not(DoShowBigMessageDialog) then
      Continue;
    DoShowBigMessageDialog:=False;
    Synchronize(_ShowBigMessageDialog);
  end;
end;

procedure TShowBigDialoxBoxThread.ShowBigMessageDialog(const Msg: string; DlgType: TMsgDlgType; Buttons: TMsgDlgButtons;
  HelpContext: Integer; DefaultButton: TMsgDlgBtn; DlgMinWidth: Integer);
begin
  FMsg:=Msg;
  FDlgType:=DlgType;
  FButtons:=Buttons;
  FHelpContext:=HelpContext;
  FDefaultButton:=DefaultButton;
  FDlgMinWidth:=DlgMinWidth;
  DoShowBigMessageDialog:=True;
end;

procedure TShowBigDialoxBoxThread._ShowBigMessageDialog;
begin
  MessageDlgBig(FMsg, FDlgType, FButtons, FHelpContext, FDefaultButton, FDlgMinWidth);
end;