exe sensor

Any specific user you're executing this with? Does this user have been logged in and started IE at least once (and configured it)?

You will need to capsulate the web browser control in its own class.
Code snippet in VB:

#Region " Classes "
    Private Class Browser
        Private Shared completed As Boolean = False
        Private Shared wb As WebBrowser

        Shared Function Main(ByVal url As String) As String
            completed = False
            wb = New WebBrowser()
            wb.ScriptErrorsSuppressed = True
            RemoveHandler wb.DocumentCompleted, AddressOf wb_DocumentCompleted
            AddHandler wb.DocumentCompleted, AddressOf wb_DocumentCompleted

            wb.Navigate(New Uri(url))
            Dim maxWait As Integer = 150  '// wait for a maximum of 15 seconds

            While Not completed AndAlso maxWait > 0
                maxWait -= 1
                Application.DoEvents()
                Thread.Sleep(100)
            End While

            If maxWait = 0 Then Return ""
            Application.DoEvents()
            Return wb.DocumentText
        End Function

        Shared Sub wb_DocumentCompleted(ByVal sender As Object, ByVal e As WebBrowserDocumentCompletedEventArgs)
            Thread.Sleep(1000)
            completed = True
        End Sub
    End Class
#End Region

'// and call it like this
Dim content As String = Browser.Main("http://prtgtoolsfamily.com/")

Thanks! :)