I have found the reason!
If I start the computer with Genmac and no xwlan widget is in xcenter the the config.sys is locked.
If I start the computer with genmac and xwlan widget present than everything is OK, config.sys is editable.

If I create the xwlan widget after the computer starts that still no go for config.sys, locked.

All I can say interesting.

>The pushbutton Connect is deactivated if you select a network

>  - that your system is already connected to, including all entries with the same network name (same SSID)
>?- which is hidden

The other computer runs winXP and I am trying to connect ad-hoc,
the scan.exe in genmac directory shows not connected, so the only reason could be hidden.

So the question is how do I make winXP not hidden(I don't use any encoding)?
Sorry don't have any access-point.