Serial Port COM 15 already in use. Try quitting any programs..

Hey guys,

i have been facing the problem as stated in the header of this topic. I have read multiple forums, and

also tried many different proposition found in those forums.

But none seem to have worked. I am using an Arduino Mega board and all worked fine until i uploaded

the program for my project for the very last time :cry: .

The execution of the program however works fine but now i cannot edit

the sketch anymore as the mentioned error is not allowing me to.

I went out and bought another arduino and the system works fine. However now i am slightly

traumatized, should the new board give way similiar to the older arduino.

Arduino pundits, any ideas with this problem would be of great help.

Thank you :slight_smile:

Is you Mega attached to a Windows computer?

I once had an issue where a "Ballpoint Serial Mouse" hijacked a COM port which I was using with an FTDI USB Arduino. I recall reading some web threads about how under certain circumstances Windows 7 thinks the FTDI is a Ballpoint Serial Mouse and installs the driver and that results in the same error message you see.

Check in Device Manager, View, Show Hidden Devices, Mice and other pointing devices. If you see Microsoft Serial Ballpoint Mouse connected disable the driver.

I think this is the same as the following Registry change which I made to disable the driver

Open Regedit. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SerMouse, and change the value "Start" from 3 to 4. Reboot."

Edit: One of the last postings with this issue turn out to be the counterfeit FTDI chip