How can I “reset” an Arduino board?

Question

I\'ve uploaded a sketch to an Arduino Uno whose loop is something like this:

void loop(){
    Serial.println(\"Hello, World!\");
}

So, now,

Answer 1

I had the very same problem today. Here is a simple solution we found to solve this issue (thanks to Anghiara):

Instead of loading your new code to the Arduino using the "upload button" (the circle with the green arrow) in your screen, use your mouse to click "Sketch" and then "Upload".

Please remember to add a delay() line to your code when working with Serial.println() and loops. I learned my lesson the hard way.