There are many instances when you have installed an OS on your EEE PC(say, windows XP) and your device is unable to even recognize find the WiFi hardware. It has happened a lot of times with me and I went nuts. It even got me into thinking that it must be just plain bad luck that the unit I got was a bad unit.
But, all what had happened the the WLan(wifi) got disabled on it’s own in the BIOS. Here is how to enable it.