Usbser.sys CDC Virtual COM Port

Hello!

I have an interesting question regarding the use of the usbser.sys built in
windows driver... I have implemented a USB CDC driver in some hardware that
I am developing hoping not to have to change Win32 applications that
currently talk to the device using an RS-232 COM Port.

I have generated a .inf file for windows XP and it installs the usbser.sys
driver correctly and it works! The Win32 apps can happily send and receive
data over USB from the device as if it was connected to an RS-232 COM port.

My problem is that the device will not remain in the device manager when
disconnected. It is of course very reasonable that when you unplug a USB
device it is removed from the device manager, however, RS-232 ports are
always available! This causes problems in the Win32 apps that are using the
port as they have to be re-started (or they at least have to re-connect to
the port) each time the device is reconnected to the PC. I wouldn't be
surprised if there is no solution to this but I was wondering if anyone had
any ideas of how to get round it? Of course, I am hoping not to have to
change the implementation of the Win32 apps as that was the whole point of
implementing USB as a virtual COM port.

Any suggestions would be most welcome!

Cheers,
Greg