Manipulating 3 IR led's on Arduino Uno
I think what you have done is a perfectly logical thing to do.  You had three programs that worked and so you pasted them all into the same file and compiled it.  The compiler spat its dummy out of the pram and you didn't understand what the h*ll went wrong.  Is that about right?

// You only need to include each header file once
#include &lt;IRremote.h&gt;

// You need to define objects to represent the leds, we could use an array but for now we'll stick to the basics (makes the code a bit longer)
IRsend irsend_led1;
IRsend irsend_led2;
IRsend irsend_led3;

// This is where you do all the setup, it only gets executed once.
// You might need to assign the pin numbers to the irsend_ledX variables here.
void setup()
{
}

// This function is called repeatedly.  You can only have one of these.
void loop() {
    // I don't understand why you have this for loop, I think you think it may have something to do with pin numbers but I don't think it does.
    // I think the data is being sent multiple times, don't know why though
    for (int i = 0; i &lt; 11; i++) {
        irsend_led1.sendNEC(0xABCDEFGH, 32); //Settings Menu
        delay(1000);
    }
    delay(1000); //1 second delay 
    for (int i = 0; i &lt; 10; i++) {
        irsend_led2.sendNEC(0xSJKLMNOP, 32); //HDMI Port
        delay(1000);
    }
    delay(1000); //1 second delay 
    for (int i = 0; i &lt; 9; i++) {
        irsend_led3.sendNEC(0xZXYRWVUG, 32); //Switch off monitor
        delay(1000);
    }
    delay(1000); //1 second delay 
}


Give that a try, it might not work, but it will be closer to what you need, I hope I have explained it well enough.  

Read the manual for the IR library and find out how to set the port numbers and if you can find out what that loop is about that might help.