Win 7's network zones feature works great; when a new connection is detected it will prompt you for:
Public - SMB file sharing & Network discovery, OFF
Work - You trust the network, SMB (128bit) ON, Network discovery, OFF
Home - Home "workgroup" - private key required for filesharing, SMB (128bit) ON, Network discovery, ON
If you need to check your existing network connection, look at your Active Network, in Network and Sharing Center
Win 8 continues this with the addition of cloud-based doc storage if you choose to accept it.
I've not been impressed with any 3rd party software-based firewalls for some time. There's no substitute for a good hardware based firewall, Sonicwalls are excellent, but expensive for the SOHO. A nice alternative is pointing your existing router to OpenDNS....