Whats wrong with system.diagnostics

[makdu]

this is my complete code

System.Diagnostics.Process.Start("cmd.exe", @"/c route print > d:\file.txt"); // Get the route print to text file
            StreamReader streamReader = new StreamReader(filePath);
            string readtext = streamReader.ReadToEnd();
            streamReader.Close();
 System.IO.File.Delete("d:\file.txt"); //Delete the  output dump file

But i am getting error in the stream reader(filepath)

Could not find file 'd:\file.txt'..

the File is getting genereated