I just plugged my arduino and click upload, it shows this error:

Arduino: 1.8.5 (Windows 7), Board: "Arduino/Genuino Uno"

Sketch uses 948 bytes (2%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
avrdude: ser_open(): can't open device "\\.\COM1": The system cannot find the file specified.

Problem uploading to board.  See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

  • 1
    Are you sure you board is appearing as COM1? Commented Mar 15, 2018 at 16:02
  • it was showing COM4 Commented Mar 17, 2018 at 10:58

2 Answers 2


either you are already using the serial port or you just didn't select the port from the arduino "Tools>port" you can always check your device's communication port using the device manager.

  • thanks for your precious time,,, the problem was selecting a right port. thanks alot Commented Mar 17, 2018 at 10:56

In the Arduino IDE check for the available ports. Be sure that the COM Port on Windows or ACMO port on Linux based OS is selected.

If the problem continues then check if the port is allowed in Windows and Linux.

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