I am using an Arduino Uno and the latest version of the Arduino IDE. I have had no problems until now, which is about a week after I first received the Arduino Uno and downloaded the software. When I upload the 'Blink' Sketch to the Arduino, I receive this error message:
"Serial port 'COM3' not found. Did you select the right one from the Tools > Serial Port menu?"
When I go to this menu, I find that it is grayed out and I cannot access it. I have read other forum posts about similar situations on Windows 7, but they do not solve the problem on Windows 8, which is the OS I am running. I have re-installed the Arduino IDE, but that did not work. The port for the Arduino Uno no longer shows up in the Device Manager, either. It appears that my computer is not recognizing the Uno at all.
I have attached a .txt document with the error message that it copied to my keyboard. Thank you for your help and I can always provide more information if needed.
check in device manager which port being detected . choose appropriate serial comport. I think in your IDE you might see 2 comport , choose other one & upload code.