Reopening serial port fails if not closed properly with CloseHandle

Question

I am working with USB device on Windows that is seen as a virtual serial port. I can communicate with the device using CreateFile and ReadFile functions, but in some cases m

Answer 1

This is certainly not normal. Windows automatically closes any handles that are left open after the process terminates. This must be a flaw in your USB device driver, although it is hard to see how it could mess this up. The ones that emulate serial ports are however notoriously lousy. Well, nothing much you can do but hope for a driver update from the manufacturer. Or a device from another manufacturer.