![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-settings_thumb.png?w=364&h=455)
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-properties.png)
Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.
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avrdude: ser_open(): can't open device "\\.\COM5": access denied. - Installation & Troubleshooting - Arduino Forum
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avrdude: ser_open(): can't open device "\\.\COM9": Access is denied. - Avrdude, stk500, Bootloader issues - Arduino Forum
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Arduino error (Ubuntu) - avrdude: ser_open(): can't open device "COM1": No such file or directory - YouTube
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Problem uploading, can't open device "\\.\COM8": Access is denied - Installation & Troubleshooting - Arduino Forum
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Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified" - Stack Overflow
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Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified" - Stack Overflow
![avrdude: ser_open(): can't open device "\\.\COM9": Access is denied. - Avrdude, stk500, Bootloader issues - Arduino Forum avrdude: ser_open(): can't open device "\\.\COM9": Access is denied. - Avrdude, stk500, Bootloader issues - Arduino Forum](https://europe1.discourse-cdn.com/arduino/optimized/4X/3/4/5/3452af44577a48236935825b34a289afdc5963b9_2_690x495.png)