try
            {
                powerPoint = new PowerPointInterop.ApplicationClass
                {
                    DisplayAlerts = PowerPointInterop.PpAlertLevel.ppAlertsNone,
                    DisplayDocumentInformationPanel = false,
                    AutomationSecurity = MsoAutomationSecurity.msoAutomationSecurityForceDisable
                };
                presentation = Open(powerPoint, inputFile, false);
                presentation.ExportAsFixedFormat(outputFile, PowerPointInterop.PpFixedFormatType.ppFixedFormatTypePDF);
            }