The latest driver 1.5 will work on Window XP SP3. I have all the latest window update.
However, you must follow the instruction on the manual. (I have to try a few different methods before I got it work!)
1. Disable built-in wireless card.
2. Uninstall any wireless driver
3. Must install the driver first before insert the card.
4. When the driver asks to insert the card, insert it.
5. The driver may complain no card found, ignore it. Choose "continue to install the driver".
6. Reboot the laptop and you should be able to find all wireless network!
I can get Excellent signal strength with 300Mb connection more than 20 feet block by a wall.