Vorneweg, I am familiar with networks quite well and have certainly committed no "operator error". I was looking for an inexpensive wireless adapter to an Old PC for occasional use in my holiday home to bring to the grid.
Its motherboard has USB 1.1, but he also has a retrofitted 2.0 card. At this date so each USB device ran each, - but not this adapter. He is recognized and integrated, but can not find a signal, even if the router is right next to it.
So one of the old interfaces on it and here he is at least a signal and can be coupled even. However, he is at a distance of about 5 meters to the router already "weak signal" and brings a throughput that is hard to describe as such.
My netbook with integrated WLAN standing right next to it and had (actually logically at only 5 meters) excellent values.
It does not matter whether I used the supplied software or have configured it directly over XP.
To rule out my old PC as source of error I have him then, of course, tried to test on another PC of the latest generation - with the same devastating results.
Conclusion: It can be the best will not say good, the part is just for a ton!