![Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it. Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.](https://gyorgybalassy.files.wordpress.com/2020/10/arduino-serial-port-in-device-manager.png)
Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.
![Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it. Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.](https://gyorgybalassy.files.wordpress.com/2020/10/arduino-port-selection.png)
Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.
![Cannot select serial port, open serial port (VSCode, Arduino, Apple M1) · Issue #1232 · microsoft/vscode-arduino · GitHub Cannot select serial port, open serial port (VSCode, Arduino, Apple M1) · Issue #1232 · microsoft/vscode-arduino · GitHub](https://user-images.githubusercontent.com/8652224/114764476-a5e1ce80-9d6c-11eb-8a3e-cb943a63beda.gif)
Cannot select serial port, open serial port (VSCode, Arduino, Apple M1) · Issue #1232 · microsoft/vscode-arduino · GitHub
![COM port number changes when connecting board on different ports or in bootloader mode – Arduino Help Center COM port number changes when connecting board on different ports or in bootloader mode – Arduino Help Center](https://support.arduino.cc/hc/article_attachments/360016532020/COM_port_changes_0.png)