How do I connect to Windows 7 dialin server from Ubuntu?

Question

I have configured an incoming connection on Windows 7 using this guide. Can anybody help me to connect to this connection from a Linux machine?

The following is the program that I run in Ubuntu with which I am able to successfully connect to incoming connection on Windows XP but not Windows 7:

#include<stdio.h>
int main()
{
 while(1)
 {
 system("sudo pppd /dev/ttyUSB0 115200 nocrtscts local user test
 password test noauth connect \"chat -v -f /etc/ppp/scripts/winserver.chat\"
 defaultroute nodetach"); //Starting PPP client
 }
 return 0;
}

The chat script in winserver.chat is as follows:

TIMEOUT 10
'' CLIENT\dCLIENT\c
CLIENTSERVER ''

The above works for Windows XP. Can anybody help me connect to windows 7?

BTW, I am using a usb-serial converter on ttyUSB0. In the terminal I put on Windows 7 I get CLIENT strings. I have also turned off firewall.

Thanks in advance