user41608: I have some problem with Arduino uno and asked here, so I have tried to work by my STM32F103C8 as alternative board, and solved my problem by this question:
Arduino Port Not detected and can not run it as root
But now I as seeing that the Arduino port again is not acceptable but I can upload the codes into the STM32F103C8 board, so I asked why this happen ?

Note : I have seen this post which the STm32F103C8 board have some port on Arduino IDE (as you can see below ):

Update:
I have seen The below post about the same problem as you can see below:
Can't open serial monitor using ST Link and STM32F103C8
But, based of the last part of above post,which is shown below,
I don't get have could i have enable the serial port connection for the STM32f103C8 Board:

I did everything as it was described in tutorial, flashing bootloader
was succes, everything went ok, but windows still can't recognize it.
I am thinking that maybe it is problem with that resistor and maybe i
have to mod it... I think I will be sticking to ST-Link for uploading
codes and USB-UART for serial. But thanks for help
And one more question, can you tell me how to reset my Blue Pill to
factory bootloader (how to delete stm32 bootloader that I installed)

Thank.

user4143: The STM32F103C8 has a native USB interface. You will only ever see a CDC/ACM (USB UART emulation) interface if you actively run code that implements a CDC/ACM interface.
The bootloader is separate to your code. I don't know what protocol the bootloader for your board uses, but it may not even have a CDC/ACM interface to it.
In short: it doesn't have a port because you haven't programmed it to have a port, and the code uploading doesn't use a port, so doesn't care.

41608: <p>I have some problem with <strong>Arduino uno</strong> and asked <a href="https://arduino.stackexchange.com/questions/84593/about-corrupted-lm35-ic-and-arduino-port-problem?noredirect=1#comment190078_84593">here</a>, so I have tried to work by my STM32F103C8 as alternative board, and solved my problem by this question:</p>
<p><a href="https://askubuntu.com/questions/1345632/arduino-port-not-detected-and-can-not-run-it-as-root/1345851#1345851">Arduino Port Not detected and can not run it as root</a></p>
<p>But now I as seeing that the Arduino port again is not acceptable but I can upload the codes into the STM32F103C8 board, so I asked why this happen ?</p>
<p><a href="https://i.stack.imgur.com/nOhxB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nOhxB.png" alt="enter image description here" /></a>
Note : I have seen <a href="https://create.arduino.cc/projecthub/akarsh98/using-a-stm32-like-an-arduino-tutorial-stm32f103c8-1073cb" rel="nofollow noreferrer">this post</a> which the STm32F103C8 board have some port on Arduino IDE (as you can see below ):</p>
<p><a href="https://i.stack.imgur.com/DmByw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DmByw.png" alt="enter image description here" /></a></p>
<p><strong>Update:</strong></p>
<p>I have seen The below post about the same problem as you can see below:</p>
<p><a href="https://www.stm32duino.com/viewtopic.php?t=90" rel="nofollow noreferrer">Can't open serial monitor using ST Link and STM32F103C8</a></p>
<p>But, based of the last part of above post,which is shown below,
I don't get have could i have enable the serial port connection for the STM32f103C8 Board:</p>
<blockquote>
<p>I did everything as it was described in tutorial, flashing bootloader
was succes, everything went ok, but windows still can't recognize it.
I am thinking that maybe it is problem with that resistor and maybe i
have to mod it... I think I will be sticking to ST-Link for uploading
codes and USB-UART for serial. But thanks for help</p>
<p>And one more question, can you tell me how to reset my Blue Pill to
factory bootloader (how to delete stm32 bootloader that I installed)</p>
</blockquote>
<p>Thank.</p>
 4143: <p>The STM32F103C8 has a native USB interface. You will only ever see a CDC/ACM (USB UART emulation) interface if you actively run code that implements a CDC/ACM interface.</p>
<p>The bootloader is separate to your code. I don't know what protocol the bootloader for your board uses, but it may not even have a CDC/ACM interface to it.</p>
<p><strong>In short: it doesn't have a port because you haven't programmed it to have a port, and the code uploading doesn't use a port, so doesn't care.</strong></p>
