COM Port Error: Port Not Found

hm, that’s weird. I don’t have that problem…
are you sure you can properly connect to the Arduino normally?
like @kll said, at least try the simplest Arduino connection first.
as a clarification, this is now the code’s using that works:

/*--------------------------------------------------------------
 Program:      port_find
 
 Description:   
 
 Date:         1 November 2012
 
 Author:       W.A. Smith, http://startingelectronics.org
 --------------------------------------------------------------*/
import processing.serial.*;

Serial ser_port;                // for serial port
PFont fnt;                      // for font
int num_ports;
boolean device_detected = false;
String[] port_list;
String detected_port = "";
boolean connected = false;
void setup() {
  size(400, 200);                         // size of application window
  background(0);                          // black background
  fnt = createFont("Arial", 16, true);    // font displayed in window

  println(Serial.list());

  // get the number of detected serial ports
  num_ports = Serial.list().length;
  // save the current list of serial ports
  port_list = new String[num_ports];
  for (int i = 0; i < num_ports; i++) {
    port_list[i] = Serial.list()[i];
  }
}

void draw()
{
  background(0);
  // display instructions to user
  textFont(fnt, 14);
  text("1. Arduino or serial device must be unplugged.", 20, 30);
  text("   (unplug device and restart this application if not)", 20, 50);
  text("2. Plug the Arduino or serial device into a USB port.", 20, 80);

  // see if Arduino or serial device was plugged in
  if ((Serial.list().length > num_ports) && !device_detected) {
    device_detected = true;
    // determine which port the device was plugge into
    boolean str_match = false;
    if (num_ports == 0) {
      detected_port = Serial.list()[0];
    } else {
      // go through the current port list
      for (int i = 0; i < Serial.list().length; i++) {
        // go through the saved port list
        for (int j = 0; j < num_ports; j++) {
          if (Serial.list()[i].equals(port_list[j])) {
            break;
          } else {
            str_match = true;
            detected_port = Serial.list()[i];
          }
        }
      }
    }
  }
  // calculate and display serial port name
  if (device_detected && ser_port == null) {

    ser_port = new Serial(this, detected_port, 9600);
    connected = true;
  }
  if (connected) {
    text("Device detected:", 20, 110);
    textFont(fnt, 18);
    text(detected_port, 20, 150);
  }
}

like the example says, start the sketch, then connect the Arduino (not the other way around).