hi what i did was just plug a wifi usb in to my pc and set my wifi up like this
1.802.11g mode
2.wep disable
3.channel 11
4.authentication mode open system
5.tx power level 0
now that bit done next step i did
then when to control panel network connections right click your lan you should have a tab called advenced click that the you should see internet connection sharing put a tick in the first box then ok that all i did then tested my wii and it worked
i hope it help you like it help me you needf any more just ask
thanks