Once it works, when it does not work!

We are dealing with a plethora of choice models of USB-Serial converters, all Chinese, and sold for a few dollars. But in general, no vendor name or model (if "generic") appears, then, for choice, hello! And as they all compete for the distributor, okay, it's coming, it has rarely the same from one quarter to the next! What distinguishes the model from that 2.50 to 15? Will they all run under all versions of Windows? I have bought 3 successively, the first shop, which I never managed to run, the other two on Amazon, the first without problems, the second recalcitrant.
After tests no wrong, the problem turned out to be the choice of the driver to install, which is not necessarily the first came on the accompanying CD (if any!). So you must try, determine the type of the chip used by the camera (see if any messages you get when you plug it provides information), successively install several drivers found by exploring the Internet and, with a little of luck and a lot of time, sometimes it works! Thus my first purchase was finally told me that he was called COM3.
Amazon could perhaps indicate, for each model, how to obtain reliable commissioning service information.