You probably didn't receive an answer as your question is too vague.
What are you trying to do? VPN clients must connect to a VPN server/gateway, and that gateway will have a bearing on the client you end up going with. Windows 7 comes with a VPN client, which may or may not be suitable for your needs.
If you're looking for a VPN service, there are a ton of service providers which either have their own preconfigured client, or will provide settings for you to use with some popular VPN clients.