Arduino Uno + MSD-11-EM stepdriver + NEMA 17
In loop add flag to change after what you desired plus a statement to check the flag.
Code below (assuming what is in for() being enough to do 4 revolutions):  

#include &lt;Stepper.h&gt;

const int stepsPerRevolution = 2100;  
Stepper myStepper(stepsPerRevolution, 8, 9, 10, 11);
bool flag = true;

void setup() {
 // set the speed at 60 rpm:
 myStepper.setSpeed(110);
 // initialize the serial port:
 Serial.begin(9600);     
}  

void loop {  
 if (flag) {  
   for(int i=0;i&lt;25;i++) {
     Serial.println("Anti-clockwise");
     myStepper.step(stepsPerRevolution);
     delay(50);
   }
   flag = false;
 }
}


This solution gives you a flexibility to add a pushbutton to change flag and do another 4 revolutions.