Here a suggestion don't use built in internet conn sharing. don't use wmwifirouter. I agree that they r great programs if you can get them to work most people have to use the newer pay version to get sucess. I have not used it sense it has went to a pay to use app.
I however do use a small 20kb file called ics.exe that you run from your cell phone. It has tons of features it auto does the nessisary reg edits to defeat any locked tethering. It works as an intermediary in between any of your connections that you want... U can use your cell for a usb wifi adapter use it to tether via the usb cable 2 pc. wifi to bluetooth sharing bluetooth to usb adapter yada yada its verry nice. It has a built in router with dhcp that allows u to set a custom ip adresses, dmz, port forwarding. Its basically a 20kb router that lets you pick 2 connections on your phone and bridge one 2 the other. It works without having the native windows internet connection sharing running bc it talks to the windows tcp/ip stacks directly.
here is the page to get it from.
http://forum.xda-developers.com/showthread.php?t=377047
I use the app on any os linux windows xp, vista 32 and 64, windows 7 beta 7000 build x32 and x64. 0 problems
one drawback of this app is b4 the wireless tethering works you have to setup an ad-hoc network on your phone manually after that launch turn on your wireless launch ics control.exe set your settings hit save then start.
on the pc u want to connect to the networked conection just select the ssid that u used to setup the ad-hoc network once connected you have internet. I have mine set to auto connect to sprint when I hit start ics.
I read so many posts on here about people complaining about wmwifirouter and or how to get it for free or where to dl version .91. It gets old after a while, with this you don't get all the pretty icons and fancy graphics of the wmwifirouter but its free and if you like it donate to the author even a $ goes a long way if everyone were to donate that.
This to me is a lot less headache then wmwifirouter as its a 20kb exe that i keep on my storage card no need to even install it i just map a shortcut to it in my programs folder.
To wireless tether select cellular \/top dropdown then tnetw12511\/ in the second dropdown box. save then hit start ics.