I had someone ask me this question a while back. I believe the problem is that the system doesn't truly see the adapter(since it's USB) as something it can share. The only things it allows to be shared is modems and actual network cards. I'm hoping they'll come up with a fix for this. Also, I doubt your modem uses VPN. I would guess it uses PPPOE. Which just asks for name authentication when you logon. If you are wishing to share the connection, look into getting an external modem with an RJ45 jack output and then purchase a router. I'm not sure about the Netgear, but the DLINK 701 and the LinkSys Router Switch combo are both pretty good. I hope that helps- PEACE