C#

object obj = myBrowser.ActiveXInstance;
IOleObject oc = obj as IOleObject;
oc.SetClientSite(this as IOleClientSite);

string authHeader = "WWW-Authenticate: Negotiate\r\n";
myBrowser.Navigate(_URL, "", null, authHeader);

public int Authenticate(ref IntPtr phwnd, ref IntPtr pszUsername, ref IntPtr pszPassword)
{
  pszUsername = Marshal.StringToCoTaskMemAuto("user");
  pszPassword = Marshal.StringToCoTaskMemAuto("pass");
  return S_OK;
}

pszUsername = Marshal.StringToCoTaskMemAuto(@"domain\user");
pszUsername = Marshal.StringToCoTaskMemAuto("user@domain");

private void fnLoadSignature()
       {
           try
           {
               SqlConnection con = new SqlConnection(conString);
               con.Open();

               string sql = "SELECT SignatureOfMember FROM CIF WHERE CIFKey = '" + txtcifkey.Text + "'";
               cmd = new SqlCommand(sql, con);
               object value = cmd.ExecuteScalar();

               byte[] data = (byte[])cmd.ExecuteScalar();
               //MemoryStream - creates a Stream whose backing store is memory. Library: System.IO
               MemoryStream strm = new MemoryStream();

               strm.Write(data, 0, data.Length);

               strm.Position = 0;

               System.Drawing.Image img = System.Drawing.Image.FromStream(strm);

               BitmapImage bi = new BitmapImage();

               bi.BeginInit();

               MemoryStream ms = new MemoryStream();

               img.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);

               ms.Seek(0, SeekOrigin.Begin);

               bi.StreamSource = ms;
    error is her------ bi = SigPics.Cursor;
               bi.EndInit();

               //SigPics.Source = bi;
           }
           catch (Exception ex)
           {
               MessageBox.Show(ex.Message);
           }
       }

private void Form1_Load(object sender, EventArgs e)
{
    pptNS.ApplicationClass powerpointApplication = null;
    pptNS.Presentation pptPresentation = null;
    pptNS.Slide pptSlide = null;
    pptNS.ShapeRange shapeRange = null;

    xlNS.ApplicationClass excelApplication = null;
    xlNS.Workbook excelWorkBook = null;
    xlNS.Worksheet targetSheet = null;
    xlNS.ChartObjects chartObjects = null;
    xlNS.ChartObject existingChartObject = null;
    xlNS.Range destRange = null;

    string paramPresentationPath = @"D:\test\Chart Slide.pptx";
    string paramWorkbookPath = @"D:\test\MyExcelData.xlsx";
    object paramMissing = Type.Missing;


    try
    {
        // Create an instance of PowerPoint.
        powerpointApplication = new pptNS.ApplicationClass();

        // Create an instance Excel.          
        excelApplication = new xlNS.ApplicationClass();

        // Open the Excel workbook containing the worksheet with the chart
        // data.
        excelWorkBook = excelApplication.Workbooks.Open(paramWorkbookPath,
                        paramMissing, paramMissing, paramMissing,
                        paramMissing, paramMissing, paramMissing,
                        paramMissing, paramMissing, paramMissing,
                        paramMissing, paramMissing, paramMissing,
                        paramMissing, paramMissing);

        // Get the worksheet that contains the chart.
        targetSheet =
            (xlNS.Worksheet)(excelWorkBook.Worksheets["Spain"]);

        // Get the ChartObjects collection for the sheet.
        chartObjects =
            (xlNS.ChartObjects)(targetSheet.ChartObjects(paramMissing));



        // Create a PowerPoint presentation.
        pptPresentation = powerpointApplication.Presentations.Add(
                            Microsoft.Office.Core.MsoTriState.msoTrue);

        // Add a blank slide to the presentation.
        pptSlide =
            pptPresentation.Slides.Add(1, pptNS.PpSlideLayout.ppLayoutBlank);

        // capture range
        //var writeRange = targetSheet.Range["A1:B15"];
        destRange = targetSheet.get_Range("A1:B15");
        //copy range
        destRange.Copy();

        // Paste the chart into the PowerPoint presentation.
        shapeRange = pptSlide.Shapes.Paste();


        // Position the chart on the slide.
        shapeRange.Left = 60;
        shapeRange.Top = 100;

        // Get or capture the chart to copy.
        existingChartObject =(xlNS.ChartObject)(chartObjects.Item(1));


        // Copy the chart from the Excel worksheet to the clipboard.
        existingChartObject.Copy();

        // Paste the chart into the PowerPoint presentation.
        shapeRange = pptSlide.Shapes.Paste();
        //Position the chart on the slide.
        shapeRange.Left = 90;
        @shapeRange.Top = 100;

        // Save the presentation.
        pptPresentation.SaveAs(paramPresentationPath,
                        pptNS.PpSaveAsFileType.ppSaveAsOpenXMLPresentation,
                        Microsoft.Office.Core.MsoTriState.msoTrue);
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
    finally
    {
        // Release the PowerPoint slide object.
        shapeRange = null;
        pptSlide = null;

        // Close and release the Presentation object.
        if (pptPresentation != null)
        {
            pptPresentation.Close();
            pptPresentation = null;
        }

        // Quit PowerPoint and release the ApplicationClass object.
        if (powerpointApplication != null)
        {
            powerpointApplication.Quit();
            powerpointApplication = null;
        }

        // Release the Excel objects.
        targetSheet = null;
        chartObjects = null;
        existingChartObject = null;

        // Close and release the Excel Workbook object.
        if (excelWorkBook != null)
        {
            excelWorkBook.Close(false, paramMissing, paramMissing);
            excelWorkBook = null;
        }

        // Quit Excel and release the ApplicationClass object.
        if (excelApplication != null)
        {
            excelApplication.Quit();
            excelApplication = null;
        }

        GC.Collect();
        GC.WaitForPendingFinalizers();

    }
}