I wouldn't have thought Windows Internet Connection Sharing would work with Apple stuff, but I may be wrong.
i have ipad Wifi 3G
its not only this gadget , i cannot use internet on any wifi device !
If you are sharing communal LAN (say, like on campus) you may not be permitted to add a wireless router to the system -- but that would be the simplest way to permit access to internet wireless for wireless equipped devices (like the iPad). You need to talk to a knowledgeable retailer and explain your setup. If on campus first speak to system administrator.
Trying to use the PC as a wireless access point might be feasible but I don't know how.