error System.unathorized access to path(hdd) how to solve it

Question

sing System;

using System.Windows.Forms;

using System.IO;

using iTextSharp.text;

using iTextSharp.text.pdf;

namespace Electronic_Book

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

private void CreateButton_Click(object sender, EventArgs e)

{

Document doc = new Document(PageSize.A4, 20f, 20f, 30f, 30f);

PdfWriter writer = PdfWriter.GetInstance (doc, new FileStream("C:\\Users", FileMode.Create));

doc.Open();

Paragraph pGraph = new Paragraph(richTextBox.Text);

doc.Add(pGraph);

doc.Close();

}

}

}

 

 

on the line saying

 

PdfWriter writer = PdfWriter.GetInstance (doc, new FileStream("C:\\Users", FileMode.Create));

 

am getting an error saying system.unathorized access to path , i am been denied to write to my own hard drive so i tried to change the security settings of the hard drive on the properties tab

to everyone full control it did not work, i did the same for individual folders it did not work too now i am out of options can someone please help me out and thanks