I'm trying to install my WiFi adapter Zyxel B-200 on my Linux Mandrake
9.1 , but it is impossible to create (or find) the wlan0 device. I
followed all the instructions of linux-wlan project page, but no way
to make it work.

Thank you for your help. (i can eventually give someone an access to
my comupter to configure it).

Joel Messas

maybe try linuxant.com and use their wlan wrapper program to actually
use windows drivers, that usually work, to load as a module for your
linux box.
Sad thing is, if you want to keep the program past the 30 day tryout
you have to pay $20. (not too bad if you're willing to pay google $15
to find a solution)
Even though linuxant.com will probably say your wifi is incompatible
try it any way. Just use google to find the windows drivers if you
don't have them to begin with.

Well, this driver is not Made for Amtel devices. Zyair B-200 is made
of an AMTEL AT76C503A.