<p>Ok... So I found a much simpler answer to this. In my device manager I just right clicked the device (Com port 4, the one that wasn't working for me) and allowed windows to update the drivers from the web.</p>

<p>This fixed my issue. Just wanted to put it out there in case anyone else was struggling</p>

CC BY-SA 4.0
2020-04-04T01:48:25.067Z
2020-04-04T01:48:25.067Z
Scubahunter
<p>Two possible solutions are given in this thread: <a href="https://forum.arduino.cc/index.php?topic=54796.0" rel="nofollow noreferrer">Upload error: avrdude: ser_open(): can't set com-state for "\.\COM17"</a></p>

<p><a href="https://forum.arduino.cc/index.php?topic=54796.msg2032153#msg2032153" rel="nofollow noreferrer">This post</a> says:</p>

<blockquote>
  <p>i am able to fix this problem very easily... just press reset button on arduino and unplug from usb and go to the arduino software installation directory (c:/program files/ arduino) and open drivers folder and open 
  dpinst-amd64 by double clicking on it and just install that if it not runs may be your system runs with 32bit and open the file below the previously opened file and install it again.. close arduino programming software and open it again and choose your board and com ports and now it should upload to your board...enjoy...</p>
</blockquote>

<p>Or try the solution from <a href="https://forum.arduino.cc/index.php?topic=54796.msg2978925#msg2978925" rel="nofollow noreferrer">this post</a>:</p>

<blockquote>
  <p>I could fix this problem! Maybe this solution will works for you:</p>
  
  <ol>
  <li><p>in device manager I had unnistalled the drivers that I had. After reconnect it then it appears in "Other dispositives" with the name
  "USB 2.0Serial". There are cases that it appears like "FT232RUSB
  UART".</p></li>
  <li><p>my serial conversor chip on arduino uno board is "CH340G". Check this on your controller boards because others like "CN480661" has
  another fix method. If you can't find this chip maybe this video could
  help you (in spanish, sorry, is where i found the solution):
  <a href="https://www.youtube.com/watch?v=F4ar5sjbZFg" rel="nofollow noreferrer">https://www.youtube.com/watch?v=F4ar5sjbZFg</a></p></li>
  <li><p>download the drivers "CH341SE" from this url: <a href="https://www.dropbox.com/s/3csnhlsbdrznbp3/CH341SER.zip?dl=0" rel="nofollow noreferrer">https://www.dropbox.com/s/3csnhlsbdrznbp3/CH341SER.zip?dl=0</a> and then
  decompress it in a folder</p></li>
  <li><p>in device manager check whether the arduino is shown (reconnect it for that if you didn't do it in `step 1) then do right click -> update
  software -> browse software in the computer -> examine or browse</p></li>
  <li><p>Now you have to search the folder in which you decompress the drivers (step 3). After then pulse accept, ignore any advertice and
  continue. Then it will install the drivers and you will be able to use
  your arduino.</p></li>
  </ol>
  
  <p>NOTE: If in this last step windows has an error you need to enable the
  unknown digital signature installation. check other tutorials for this</p>
</blockquote>

<p>These seem to be the only two solutions that worked for other people experiencing the same issue.</p>

CC BY-SA 4.0
2019-04-26T10:48:32.173Z
2019-04-26T10:48:32.173Z
Greenonline
<p>I've been having trouble uploading the TH3DUF_R2 firmware to my CR-10.  I've already successfully flashed the bootloader using my Arduino,  but when I try to upload the bootloader I get this error:</p>

<p><code>avrdude: ser_open(): can't set com-state for "\\.\COM4"</code></p>

<p>Things I've tried:</p>

<ul>
<li>Changing the usb drivers</li>
<li>Changing the baud rate</li>
<li>Using a different computers without any other usb devices</li>
</ul>

<p>My printer is not functional right now with just a bootloader and no firmware, so I'm not really sure where to go from here.</p>

CC BY-SA 4.0
2019-04-05T01:34:43.487Z
Might be a dumb question but have you checked to make sure you are using the right com port?
Dr. Mantis Tobbogan
CC BY-SA 4.0
2019-04-05T04:59:15.350Z
And the right baudrate?
Trish
CC BY-SA 4.0
2019-04-07T20:44:23.437Z
Yeah, I've tried different baud rates, and I'm definitely using the right COM port.
Rhezner
CC BY-SA 4.0
2019-04-27T17:19:45.363Z
This happens with a busy port, so your card is operating and blocking the communication. I had the same problem two years ago.
Fernando Baltazar
CC BY-SA 4.0
2019-04-27T17:27:32.120Z
Just unplug the arduino, keep all ready to upload (fully compiled) then connect the arduino and just after the sound of detection device of windows click the command upload. This way you don't give the chance to arduino starts to oparate and sature the comunication from usb port.
Fernando Baltazar
<troubleshooting><creality-cr-10><usb>
Error when trying to upload firmware to cr-10
Rhezner
# Error when trying to upload firmware to cr-10

(Asked by: username_0 on 2019-04-04)

I've been having trouble uploading the TH3DUF\_R2 firmware to my CR-10. I've already successfully flashed the bootloader using my Arduino, but when I try to upload the bootloader I get this error:

`avrdude: ser_open(): can't set com-state for "\\.\COM4"`

Things I've tried:

* Changing the usb drivers
* Changing the baud rate
* Using a different computers without any other usb devices

My printer is not functional right now with just a bootloader and no firmware, so I'm not really sure where to go from here.

**Tags:** troubleshooting, creality-cr-10, usb
> **Comments:**
> **username_1**: Might be a dumb question but have you checked to make sure you are using the right com port?  
> **username_2**: And the right baudrate?  
> **username_0**: Yeah, I've tried different baud rates, and I'm definitely using the right COM port.  
> **username_3**: This happens with a busy port, so your card is operating and blocking the communication. I had the same problem two years ago.  
> **username_3**: Just unplug the arduino, keep all ready to upload (fully compiled) then connect the arduino and just after the sound of detection device of windows click the command upload. This way you don't give the chance to arduino starts to oparate and sature the comunication from usb port.  

---

## 2 answers

### Answer by username_4 on 2020-04-04. Score: 1

Ok... So I found a much simpler answer to this. In my device manager I just right clicked the device (Com port 4, the one that wasn't working for me) and allowed windows to update the drivers from the web.

This fixed my issue. Just wanted to put it out there in case anyone else was struggling


---

### Answer by username_5 on 2019-04-26. Score: 1

Two possible solutions are given in this thread: [Upload error: avrdude: ser\_open(): can't set com-state for "\.\COM17"](https://forum.arduino.cc/index.php?topic=54796.0)

[This post](https://forum.arduino.cc/index.php?topic=54796.msg2032153#msg2032153) says:

> i am able to fix this problem very easily... just press reset button on arduino and unplug from usb and go to the arduino software installation directory (c:/program files/ arduino) and open drivers folder and open
> dpinst-amd64 by double clicking on it and just install that if it not runs may be your system runs with 32bit and open the file below the previously opened file and install it again.. close arduino programming software and open it again and choose your board and com ports and now it should upload to your board...enjoy...

Or try the solution from [this post](https://forum.arduino.cc/index.php?topic=54796.msg2978925#msg2978925):

> I could fix this problem! Maybe this solution will works for you:
>
> 1. in device manager I had unnistalled the drivers that I had. After reconnect it then it appears in "Other dispositives" with the name
>    "USB 2.0Serial". There are cases that it appears like "FT232RUSB
>    UART".
> 2. my serial conversor chip on arduino uno board is "CH340G". Check this on your controller boards because others like "CN480661" has
>    another fix method. If you can't find this chip maybe this video could
>    help you (in spanish, sorry, is where i found the solution):
>    <https://www.youtube.com/watch?v=F4ar5sjbZFg>
> 3. download the drivers "CH341SE" from this url: <https://www.dropbox.com/s/3csnhlsbdrznbp3/CH341SER.zip?dl=0> and then
>    decompress it in a folder
> 4. in device manager check whether the arduino is shown (reconnect it for that if you didn't do it in `step 1) then do right click -> update
>    software -> browse software in the computer -> examine or browse
> 5. Now you have to search the folder in which you decompress the drivers (step 3). After then pulse accept, ignore any advertice and
>    continue. Then it will install the drivers and you will be able to use
>    your arduino.
>
> NOTE: If in this last step windows has an error you need to enable the
> unknown digital signature installation. check other tutorials for this

These seem to be the only two solutions that worked for other people experiencing the same issue.


---

