All you need to do is share the USB wifi adapter as an internet connection using Windows ICS (if you have 2000 or XP). Right-click the USB wireless connection icon, go to
Properties, select the
Advanced tab and enable Internet connection sharing.
Just make sure you do not play with the IP address settings with the ICS computer's Ethernet adapter or it will break ICS. You will also need to disable DHCP on your router to prevent it conflicting with ICS.
If the WLAN uses the IP address range 192.168.0.x then this solution will not work unless you install a third-party internet sharing program on the PC.
I've attached a quick diagram that will hopefully explain.
