C# – Access to the path Denied when uploading excel file

When uploading an excel file I am receiving this error, can anyone help me?

Access to the path
'C:\Data\IronElements\Upload\AUMData\20101202
031815.xlsx' is denied. Description: An unhandled exception occurred during
the execution of the current web
request. Please review the stack trace
for more information about the error
and where it originated in the code.

Exception Details:
System.UnauthorizedAccessException:
Access to the path
'C:\Data\IronElements\Upload\AUMData\20101202
031815.xlsx' is denied.

ASP.NET is not authorized to access
the requested resource. Consider
granting access rights to the resource
to the ASP.NET request identity.
ASP.NET has a base process identity
(typically {MACHINE}\ASPNET on IIS 5
or Network Service on IIS 6) that is
used if the application is not
impersonating. If the application is
impersonating via , the identity
will be the anonymous user (typically
IUSR_MACHINENAME) or the authenticated
request user.

To grant ASP.NET access to a file,
right-click the file in Explorer,
choose "Properties" and select the
Security tab. Click "Add" to add the
appropriate user or group. Highlight
the ASP.NET account, and check the
boxes for the desired access.

Source Error:

An unhandled exception was generated
during the execution of the current
web request. Information regarding the
origin and location of the exception
can be identified using the exception
stack trace below.

My Code behind file has the following syntax

DateTime date = DateTime.Now;
                string FileName = Convert.ToString(date.ToString("yyyyMMdd hhmmss"));
                Directory.CreateDirectory("C:\\Data\\IronElements\\Upload\\AUMData\\Schema");
                doesFileExists("C:\\Data\\IronElements\\Upload\\AUMData\\Schema");
                fileUpload.PostedFile.SaveAs("C:\\Data\\IronElements\\Upload\\AUMData\\" + FileName + ".xlsx");
                System.Threading.Thread.Sleep(5000);
                string connectionString = WebConfigurationManager.ConnectionStrings["SQLConnection"].ConnectionString;
                SqlConnection SqlConnect = new SqlConnection(connectionString);

                try
                {
                    SqlConnect.Open();
                    SqlCommand cmdAssetUnderManagement = new SqlCommand("Exec_Insert_AUMAssetValue", SqlConnect);
                    cmdAssetUnderManagement.CommandType = CommandType.StoredProcedure;
                    cmdAssetUnderManagement.ExecuteNonQuery();

                }


                catch (Exception ex)
                {
                    Response.Write(ex.Message);
                }
                finally
                {
                    SqlConnect.Close();
                }
                lblAUMTA.Visible = true;
                lblAUMTA.Text = "File Upload Completed";
            }
    private void doesFileExists(string p)
            {
                p = string.Concat(p, "\\AUMSchema.xlsx");
                if (!File.Exists(p))
                {
                    fileUpload.PostedFile.SaveAs("C:\\Data\\IronElements\\Upload\\AUMData\\Schema\\AUMSchema.xlsx");
                }
            }