HP laptop wireless to Desktop PC

I just installed a wireless adapter in a desktop pc to connect a HP
pavilion notebook.

I shared the Internet connection on the desktop and the HP can surft
without probleem. Also one PC can ping to the other, but there seems
to be a trouble to connect the Windows networks (both with XPhome)
Each PC see only itself.

For that reason I want to trying changing the channel. On the desktop
it is easy 'cause the NIC came with setup soft but I just can't find
out how to do this on the HP notebook ...

Is there a good utility (running under XP) to see which channel is in
use and eventualy change it ?


Regards,
Georges