Arduino IDE does not save the script to the sparkfun arduino uno board in windows 7 · Issue #1992 · arduino/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/360016539199/COM_port_changes_1.png)
COM port number changes when connecting board on different ports or in bootloader mode – Arduino Help Center
![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.
![Arduino Micro - IDE trying to upload to wrong COM Port ! - Installation & Troubleshooting - Arduino Forum Arduino Micro - IDE trying to upload to wrong COM Port ! - Installation & Troubleshooting - Arduino Forum](https://europe1.discourse-cdn.com/arduino/original/4X/6/1/c/61c55bfabce3bbe9224c4cfd5e9bf1345487e26b.png)