Please explain.
The installer will attemp to install the COM port driver but depending on your Windows 11 configuation it may not allow the driver to be installed.
The OpenGD77 firmware acts as a standard CDCACM aka USB Serial COM port, and I think Window 11 uses its own CDC ACM driver when an OpenGD77 radio is attached with the firmware installed and the radio operating normally.
Because the CPS may not have been able to install the normal USB driver, and Windows is using its own, you will need to manually select the COM port in when the CPS communicates with the radio.
Depending on your radio type, in bootloader mode the radio will either appear as a STM DFU device or a USB HID device. This is because the bootloader is not written by us and we don't replace it, as this is very high risk, hence the OpenGD77 CPS interfaces to whichever USB device type the radio exhibits.
The USB HID device is driverless as its built into all operating systems
The STM DFU device gets installed automatically by Windows but sometimes Windows installs an incompatible DFU driver from STM becasue they have 2 completely different DFU drivers which are not compatible with each other.
In which case, see the many other posts about where to download the correct STM DFU driver.