Amazon VPN Configuration

I need you to setup a VPN connection between my local windows machine (windows 7) and Amazon VPC. I have already configured Amaon VPC with 2 instance (Linux redhat) -- VPC with Public and Private Subnets Please note that in order to setup VPN, I do not want to go for any hardware configuration or hardware purchase. I only want to install some software (Cisco or openvpn) for this purpose. Also if Cisco is not free, I will only go for OpenVPN or any other open source VPN software. If you know how exactly this can be done, I am sure that it will not be a job of more than 2-3 hour. Also when you set up VPN, I should be able to coonect to Amazon instance from my local machine using internal ip address. If I cannot connect, there will be no meaning of setting up VPN.