user62678: Please help with this error.
Arduino: 1.8.10 (Windows 10), Board: "Arduino Uno"
Sketch uses 882 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 "\.\COM4": Access is denied.
Windows 10 Pro
Arduino UNO ATmeg 328P-PU
Have never been able to Upload a sketch. 
Pin 13 and Orange LED blink at 1 second

user16591: Welcome to the Stack Exchange and on the Arduino World.
Just a note: Since yesterday there is a new version of Arduino IDE (the last version is now 1.8.11).
When you buy an Arduino, a default sketch is already present. This will blink your LED (pin13) with a 1 second interval. This just mean that your Arduino is working and has a bootloader.
To program it, you need to know which COM port is created for your Arduino module:   

Press WIN-'R' (execute application)  
Write devmgmt.msc

Check the COM port to see wich COM port was used for your Arduino.
This is the only cause, the message could appear if you use a standard USB-cable connected to your standard Arduino UNO board.

62678: <p>Please help with this error.
Arduino: 1.8.10 (Windows 10), Board: "Arduino Uno"</p>

<p>Sketch uses 882 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 "\.\COM4": Access is denied.</p>

<p>Windows 10 Pro
Arduino UNO ATmeg 328P-PU
Have never been able to Upload a sketch. 
Pin 13 and Orange LED blink at 1 second</p>
 16591: <p>Welcome to the Stack Exchange and on the Arduino World.</p>

<p>Just a note: Since yesterday there is a new version of Arduino IDE (the last version is now 1.8.11).</p>

<p>When you buy an Arduino, a default sketch is already present. This will blink your LED (pin13) with a 1 second interval. This just mean that your Arduino is working and has a bootloader.</p>

<p>To program it, you need to know which COM port is created for your Arduino module:   </p>

<ul>
<li>Press WIN-'R' (execute application)  </li>
<li>Write <code>devmgmt.msc</code></li>
</ul>

<p>Check the COM port to see wich COM port was used for your Arduino.</p>

<p>This is the only cause, the message could appear if you use a standard USB-cable connected to your standard Arduino UNO board.</p>
