Okay, completely new to this, I uploaded the code which did not worked so i removed my LED and closed the arduino program but the L led is still blinking like it was before. I want to remove the earlier code from the arduino to add a new one. How do I do this ? Please Help urgently...
P.S. : I want to say that i want to reset my arduino or bring it back like it was before. How to huh ?
upload a new sketch with no thing in it.. just
void setup(){}
void loop(){}
An Arduino holds its code until it is overwritten by a new program called a sketch.
As Eddy proposed sending a (nearly) empty sketch can be sent to the Arduino to make it do "as little as possible".
There is a tool called AVRDUDE.EXE that does the uploading (and can also download) the binary image to an Arduino. Don't know for sure but it should be possible with that tool to write all 00's to the Arduino. But this is far more work than uploading an empty sketch.