My experience of the adapter is with windows 7. It plugged into a USB port and once the (supplied) CD installed the software I was able to get online. The signal strength is exactly the same as my laptop, at just over half of the ethernet wired strength (this is to be expected for WIFI signals). This is ideal for all normal internet usage and I haven't had any lag, even when streaming videos.
The fact that this device has a dual ariel and can be positioned away from the metal casing of the computer means that if anything can pick up a WIFI signal....this will. It also means that you avoid opening up the computer to install an internal card. Very happy with the performance.