Seems that most here are not understanding my question: Is the firewall that is provided with Windows 7 sufficient to protect my computer or must I look elsewhere?
The answer is both yes and no to what you asked.
The Windows firewall is fine for most situations needing inbound protection. And if you’re behind a NAT router you don’t really even need that. Outbound protection is a completely different thing, and would require some of the software packages recommended upthread.