Hello, I am very new to this arduino stuff and had the same problem. I am wondering why whenever I upload a sketch to my arduino (uno) from my windows (64 bit) hp computer, the arduino app always says [at the bottom] that the serial port com3 is in use with another program and that it tells you to quit it. Any help is greatly appreciated. Thank you. conmor2125
Most likely, there is an application that keeps using the serial port. (I'm making the assumption that the upload fails.)
Do you have any software that uses virtual com ports, like drivers for a wireless-data device?
I will have to look into that. Thanks. By the way, is there a way you know that I could see if there is any programs using the com ports? I do not have drivers for a wireless data device, and the upload did fail. Is there a way to switch com ports on Windows 7 64 bit? [as you can tell, I am not a computer genius] :) I have downloaded and installed the latest drivers for my arduino uno. It just seems to be the com port #3 is always in use. Thank you again, Conmor2125 :D