Nothing is working even though every thing is right & it is new? I have bought a new 'SunFounder Arduino uno R3' and started learning, the first lesson was 'Blinking LED' of course.

I have done it all, connected Jumper-Wires and the Sensor and the LED light, I wrote the code:

const int ledPin = 9;
void setup()
{
   pinMode(ledPin,OUTPUT);
}
void loop()
{
   digitalWrite(ledPin,HIGH);
   delay(500);               
   digitalWrite(ledPin,LOW); 
   delay(500);
}


BUT NOTHING HAPPENS !!!, I checked out every thing over and over, it just does not work ???
Every thing is well about the board and the UNO R3 it is new.
I have checked the code and the connections and checked the Device Manager to know that the serial port of the arduino is 'COM3'...
I dont know what is wrong with it ?!!
In these cases it helps to break down the problem in pieces.

If the internal LED on pin 13 blinks with your code it means that the software side is OK so far (code, Arduino type, compiling, uploading etc), so I suggest looking at the physical side of things.

Do you have a multimeter available? If so, connect it between pin 13 and ground and it should show you if the output works.

Finally, is the LED working? When you connect it between 5V and GND (with a resistor!) it should light up.