my device manager in windows 7 detects me the arduino device in com22 and wen i try to upload it says the the com22 is already in use.the previous program that i have uploaded was hello arduino !! Serial.println . I am not able to overwrite it . HELP ME GUYS
Sometimes the Arduino IDE does not close the COM port. Try closing all instances of the Arduino IDE, then re-open one and try again. If that doesn't work, re-boot your computer to free up the COM port.