In Windows 7 the driver for the CH340G creates : USB-SERIAL CH340 (COM3)
Manufacturer : www.winchiphead.com
and sometimes: Manufacturer : wch.cn
File : 3.30 built by: WinDDK
Name of fysical device: \Device\USBPD0-14
I don't know if you can return the board. Does the description say something with CH340G ?
You bought a very cheap fake/clone board, and that is what you got.