how to build a vpn server?

hi there,

i met some difficulties while building my own vpn server.

i do these steps:

apt-get install pptpd

modify /etc/pptpd.conf and added these lines in the end of the file:

localip 192.168.0.1

remoteip 192.168.1.2-200

modify /etc/ppp/chap-secert anded these lines in the end of the file:

username * password *

then i restart the pptpd.

/etc/init.d/pptpd restart

but when i want to use my windows client to connect to it,my windows told me cannot connect to vpn server.

what shall i do?

thx