WebBrowser1.Navigate("URL", "", paramInByte, "Content-Type:application/x-www-form-urlencoded")

'scroll to the picture, so we have a WebBrowser object just like a picture box
For Each i As HtmlElement In w.Document.GetElementsByTagName("img")
    If i.GetAttribute("src").Contains("here string to identify captcha image") Then
        i.ScrollIntoView(True)
    End If
Next

'Create bitmap
Dim bmp As New Bitmap(w.Width, w.Height, Imaging.PixelFormat.Format32bppArgb)
Dim g As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(bmp)
Dim hdc As IntPtr = g.GetHdc

'Do the Drawing
Dim pUnk As IntPtr = System.Runtime.InteropServices.Marshal.GetIUnknownForObject(w.ActiveXInstance)
OLE32.OleDraw(pUnk, 1, hdc, New Rectangle(0, 0, w.Width, w.Height))
System.Runtime.InteropServices.Marshal.Release(pUnk)

'Release DC and dispose
g.ReleaseHdc(hdc)
g.Dispose()

Public Class OLE32
    Public Declare Function OleDraw Lib "ole32.dll" (ByVal pUnk As IntPtr, ByVal dwAspect As Integer, ByVal hdcDraw As IntPtr, ByRef lprcBounds As Rectangle) As Integer
End Class