Access denied error rise while get a path some processes. How I resolve it. Please help me.

foreach (Process p in Process.GetProcesses())
            {
                if (p.MainModule.FileName == "App.exe")
                {
                    string procFile;
                    try
                    {
                        procFile = p.Modules[0].FileName;
                    }
                    catch (Win32Exception)
                    {
                        procFile = "n/a";
                    }

                textBox1.Text+=(string.Format("Process {0}: {1}", p.ProcessName, procFile));
                }
            }