need help: "The requested operation requires elevation"

Question

I am trying to execute some series of statements in diskpart utility through C#. But i keep getting exception at p.start() that "The requested operation requires elevation" . I have tried application manifest file to run this as administrator but no use:

Process p = new Process();                                    // new instance of Process class
p.StartInfo.UseShellExecute = false;                          // do not start a new shell
p.StartInfo.RedirectStandardOutput = true;                    // Redirects the on screen results
p.StartInfo.FileName = "diskpart";                             // executable to run
p.StartInfo.RedirectStandardInput = true;                     // Redirects the input commands
p.Start();                                                    // Starts the process
p.StandardInput.WriteLine("select disk 1");                   // Issues commands to diskpart
p.StandardInput.WriteLine("clean");                           //   |
p.StandardInput.WriteLine("create partition primary");        //   |
p.StandardInput.WriteLine("select partition 1");              //   |
p.StandardInput.WriteLine("format fs=ntfs quick");            //   |
p.StandardInput.WriteLine("active");                          //   |
p.StandardInput.WriteLine("assign");                          //   |
p.StandardInput.WriteLine("exit");                            // _\|/_
string output = p.StandardOutput.ReadToEnd();                 // Places the output to a variable
p.WaitForExit();                                              // Waits for the exe to finish
MessageBox.Show(output);