hm, i dont know if it worked to me, i did it: i have a server where the icon on task bar dont apear, and i have a server where it apear, so i copy nwindow.dll and does not appear anymore. btw my client is c5. I will try find a l2walker to c5 and try it :)
edit: erm , does work, dont login =/ just loging in solo l2j.