Serial Port Already in Use-but there's no other program using it. Windows 8

Hey, so I've been working with Arduino for a little bit, but this is the first time I've had a problem with this. I'm working with and Uno on Windows 8, and anytime I try to upload a sketch onto my board, the Serial Com error above pops up. The project I'm working on involves PureData talking to Arduino through the serial port, but this error occurs even when I haven't opened up pd extended. Does anyone have any idea what the problem is/how I can fix this?

It sounds like the Pure Data app is not closing the serial port properly when it exits.

Perhaps, but this error occurs on multiple computers when pd extended is not even open. I'll check and see if maybe it's running in the background.

groundfungus: It sounds like the Pure Data app is not closing the serial port properly when it exits.

Sounds like the same kind of thing as when Windows says you mustn't remove your flash drive because it's in use, and you know full well that it isn't.

Advanced Serial Port Monitor (http://www.aggsoft.com/serial-port-monitor.htm) may help you.

  1. Download the trial version.
  2. Install
  3. Start the program with elevated administrator privileges (Right-click over the program icon and select "Run as administrator").
  4. Switch to the manual mode (Mode - Manual)
  5. Select your port.
  6. Try to open the port.

the program will show a process that use this port.

My Makerbot software is the culprit on my iMac - it adds a background service that runs at startup. I have to start their software and select 'stop background service' before I can program the arduino. It's the 'converyd' daemon. And you can't 'kill' from a console because something else starts it back up immediately. Just do it from the Makerbot Desktop software.