This is not an installation issue unless the INF file is incorrect.  Here is more information:  This concerns Amateur radios with built in CP210x USB devices.
Both Icom and Yaesu radios use the CP210x USB UART drivers.  Both Icom and Yaesu supply version 6.xx drivers.  These work correctly.  However I have run into a number of cases in the last few weeks where Windows update has replaced these with your CP210x Universal Windows Drivers.  There is a bug in those version 10,x drivers.  A simple Port.Open() where the baud rate is greater than 19200 fails saying the maximum supported baud rate is 23800.  This happens in Microsoft .NET serial port class.  Other software NOT written using .NET works correctly.
This must be fixed!

PLEASE!!! There is another issue!

Using the .NET serial port class (.NET 4.0) will fail on a port.Open(comport, 115200);  You driver reports that the maximum baud rate is 23800.

Tom

More details....

Upon doing a port open in .NET I receive an exception that the maximum baud rate is 23800!

The code is very simple....NET 4.0 where baud is 115200

                port = new SerialPort(comport, baud);
                port.Open();

Then the exception happens that the maximum baud rate is 23800

I have a funny problem.  I have two computers out of a few hundred that connect to a serial port at 115200.  They can connect fine at 19200.

Here is the trace from a serial port sniffer.

19200 Baud Trace:

[29/04/2018 19:05:26] - Open port COM3 (C:\Program Files (x86)\VA2FSQ\Win4IcomSuite-v1.00-x64\Win4IcomSuite.exe)
 
[29/04/2018 19:05:26]Changed baudrate: 19200
 
[29/04/2018 19:05:26]Disabled RTS
 
[29/04/2018 19:05:26]Disabled DTR
 
[29/04/2018 19:05:26]Changed line control: Databits 8, Parity none, StopBits 1
 
[29/04/2018 19:05:26]Changed flow control: ControlHandShake 0x00, FlowReplace 0x00, XonLimit 55546, XoffLimit 55546
 
Here is at 115200

[29/04/2018 19:10:43] - Open port COM3 (C:\Program Files (x86)\VA2FSQ\Win4IcomSuite-v1.00-x64\Win4IcomSuite.exe)
 
[29/04/2018 19:10:43] - Close port COM3
 
[29/04/2018 19:10:43] - Open port COM3 (C:\Program Files (x86)\VA2FSQ\Win4IcomSuite-v1.00-x64\Win4IcomSuite.exe)
 
[29/04/2018 19:10:43] - Close port COM3
 
It just won't connect.  I am using the .NET serial port class.

Any ideas?

Thanks