Compared to the other two adapters, a generic and a Atheros AR9285, this AWUS036H adapter brings on average two-bar graphs over to nearby hotspots of my apartment. So I now have a perfectly stable and fast connection.
As Windows 7 (Home Premium) I got the best results by not using the supplied CD, but by downloading the driver from the manufacturer's website (indicated on the package) in the section Support / Downloads. The zip file of the driver is called "11G_ETSI_WIN7" and called for "European Power Control".
Once installed this driver (reboot needed), it is imperative to configure two items in "ALFA Wireless LAN Utility": 1) "Advanced" tab: put "frequency map" to "France" 2) "General" tab: Making Cursor "TX Power" at least 40%. There you go.
If not careful where you buy it because it is very fake (under the original adapter you must find a hologram label "Alfa Network" with "TAIWAN" in several colors). That sold by Amazon / ECON is an original.
I definitely recommend this product.