user14515: I installed the new IDE Environment 1.6.6 and I got this error when compiling a program. I am using an Arduino Uno
avrdude: ser_open(): can't open device "\\.\COM4": access denied

I need your help.

user36743: 
I think you used "Eclipse" and "Arduino" at the same time. so, I guess that a "com4 Port" conflict has occurred and the upload could not was done. 



restart  your computer and try to open "Arduino" first and upload. not open "Eclipse" at the same time.


14515: <p>I installed the new IDE Environment 1.6.6 and I got this error when compiling a program. I am using an Arduino Uno</p>

<pre><code>avrdude: ser_open(): can't open device "\\.\COM4": access denied
</code></pre>

<p>I need your help.</p>
 36743: <ul>
<li>I think you used "Eclipse" and "Arduino" at the same time. so, I guess that a "com4 Port" conflict has occurred and the upload could not was done. </li>
</ul>

<hr>

<ul>
<li>restart  your computer and try to open "Arduino" first and upload. not open "Eclipse" at the same time.</li>
</ul>
