The brand-new Netgear "Nighthawk" WiFi adapter I bought last week just went casters-up.
The used one for this computer arrived this morning, installed easily, and gives me the full 250+MB download speeds I get with an Ethernet connection.
The one I bought a year or so ago for the wife's PC is also working A-OK. I tried both of them on the weather server and it popped right back up on the WLAN, and the one from the weather server is dead as doornail on this PC. No blinky lights, and it's stone cold while these normally run warm-to-the-touch.
Time to box it up and drag it back to Best Buy......