Need Help With PPTP And Static IPs

I followed this tutorial: ~~[http://www.ubuntugeek.com/howto-pptp-vpn-server-with-ubuntu-10-04-lucid-lynx.html" target="_blank">](http://www.ubuntugeek.com/howto-pptp-vp … -lynx.html">http://www.ubuntugeek.com/howto-pptp-vpn-server-with-ubuntu-10-04-lucid-lynx.html](

to setup my server as a PPTP VPN server. I went through everything and when I try to connect in Windows 7 I get past the verifying username and password and connecting with PPTP but when I get to registering computer on network it stops working. I can't get any further than that when connecting.

I think this might be an issue with my Private IP address since it isn't listed when I type ifconfig. Can someone help me out with telling me what's wrong and telling me how to enable the private IP address.