You're looking in the right place.  If you don't see your USB Serial Port device under Device Manager > Ports, then you might need to install a different/additional driver.  That's how my adapter works.  And fyi once you get it listed there, if needed you can change the COM port number to avoid conflicts.  To do that, open the device's properties and go to Port Settings > Advanced, where you'll find a "COM Port Number" dropdown.  And just under Port Settings (i.e. outside of the Advanced area), you'll see the typical array of serial port settings that you might need to set a certain way to interface with whatever device you're connecting to via serial.

When I did not find this information by myself, then I called "Dell Technical Support". After hearing my problem, they transferred me to the "Customer Care" and they took remote access to my computer. When the "Customer Care" could not get the solution, they transferred my call to the "software department". Then the "software department" transferred my call to the "hardware warranty department" and then they transferred me to the "Dell Solution Center". "Dell Solution Center" then transferred my call to the "Dell Support Center" and, "Dell Support Center" told me that they are unable to help me.

It seems that they are just passing the ball to the other department and are reluctant in solving the issue. I am very disappointed with them.

Thanks jphughan. Could you please give me the link/name of the driver that I need to install so that I will be able to find the "Ports (COM & LPT)" option in my "Device Manager"? At present, I am not finding the "Ports (COM & LPT)" option in my "Device Manager".

I am using Inspiron 7386, Windows 10, 64 bit.

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@User_name111 wrote:

Thanks jphughan. Could you please give me the link/name of the driver that I need to install so that I will be able to find the "Ports (COM & LPT)" option in my "Device Manager"? At present, I am not finding the "Ports (COM & LPT)" option in my "Device Manager".

I am using Inspiron 7386, Windows 10, 64 bit.

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Hey there, unfortunately there isn't a universal USB to serial port driver.  The driver should be provided by whoever makes the specific adapter you're using.  It is certainly the case that adapters from multiple vendors sometimes use the same chipset internally (FTDI is a popular choice for USB to serial interfaces) and therefore the same driver might work on adapters from multiple vendors, but that isn't a guarantee.  And just out of curiosity, have you tested this adapter on another system to see if it comes up properly there either?  If it doesn't, it could also be a hardware/firmware issue with the adapter itself.

Hello Jphughan,

I am trying to connect a PLC (Programmable Logic Controller) with my Laptop. The adapter/USB cable of the PLC is working fine with other devices but, it is not working with Dell laptops only since I cannot find the "USB COM port number" of the Dell laptops. I have asked the vendor of the PLC for providing me with the driver and now waiting for their reply. Please let me know if you have any suggestions for me.

The vendor of the PLC (that I am trying to connect via USB COM port) recently told me that they cannot provide me any driver also told to contact with Dell in this regard. So, can anyone please give me any suggestion in this regard?

Unfortunately no, and I have no idea why they would have told you to contact Dell. Drivers and COM port issues would not relate to specific to system models. They relate to operating system versions, because the operating system would require certain drivers and the operating system assigns COM ports (which the user can change through Device Manager).  Also, just to clarify something, in your original post you asked for the "USB serial port COM number" of your Dell system.  There isn't a COM number for the entire system.  The COM number is assigned to the USB serial port adapter itself whenever it's connected, and again that's all handled by Windows, not the system.  If there was a known issue with your device when trying to use it with certain versions of Windows, that might be understandable, but this wouldn't be a situation where this USB device doesn't work with Dell laptops but works with some other vendor's laptops.

But since you mention this works with other devices, what are these other devices that work properly with this adapter, and what version(s) of Windows are they running?

I have attached the screenshot of the my "Device Manager". I also have attached the screenshot of the PLC software where I have to input the "USB COM port number". 

My Dell laptop is Windows 10. The PLC is being connected properly with my desktop computer which is also Windows 10.

The vendor previously gave me a driver (they told that it was mandatory to install for connecting to ANY kind of computers) while buying the PLCs which I had installed but found no result.

The vendor also suggested me to try to connect the USB of the PLC to a "9 pin serial port" and then connect that "9-pin serial port" to my Dell laptop. But I think that I will not be succeeded because I am not even able to see the ports in the Device Manager whether it a USB port or a "9-pin serial port"

If you have a desktop computer running Windows 10 where the adapter works fine and you can see it under the Ports section of Device Manager, then unfortunately at this point I'm not sure what to tell you.  Anything else I'd want to check would require having access to both systems and time spent troubleshooting rather than just making suggestions in forum posts.  Sorry!