Not sure where these negative reviews are coming from. I might humbly suggest that some of these people check their router. A wireless adapter is ONLY as good as the router or other wifi it is trying to connect to. AND, your poor router has to broadcast through anything between it and its receiver. If you have a pile of books on top of it or something, expect crappy reception. The same, if your router is in the basement and your computer is three floors up with stone or sheet metal between the two. That being said, this is about as powerful as it gets with standard hardware when trying to connect to wireless....at least on the reception end. It is, in essence, a very high quality antenna. If it's not working, the problem is probably, your network broadcast is of unreasonably crappy quality or you are asking too much of standard wireless (like trying to broadcast to the house next door on your laptop....we've all done it).
Bottom line....installation was plug and play. I plug it in, 30 seconds later, the operating system has installed drivers for it. If you want, you can use the included installation disk. But that isn't necessary. Or maybe it is....I still used XP (gasp....infidel).
Who needs this product. Two people. The guy who is trying to connect to his wireless just a little farther than is wise to and can't quite make it happen without a really good antenna. And the guy with a really good router who is pissed off because the wireless card in his laptop is just not good enough to make full use of his connection. The issue is there are cheaper adapters and most of them work just as good as this one because your router/wireless is crappy. Better router before better adapter. Most people with a computer more than a year or two old could probably benefit from both.
Also, check your cable modem if you have a home wireless network. There is simply no point if your internet access isn't good enough to support this. Most are, some are not.