In any case, Windows(NT3.5-2K3) NIC failover is via a virtual NIC made from to 2 physical NICs.
Usually the methods I have seen are using both NICs (or more if you have them) in a Bonded Configuration, provided your switch can support it. That way you get more bandwidth availability (even if not the point) and failing of one NIC with the bonding will go into either degraded state or non-bonded state but still be connected. This depends on you NIC manufacturer.
Microsoft uses this kind of setup in the "cluster mode" much of the time, so it does work. I can't find any non-cluster specific setup.
It may appear that this is a built-in thing as well... you just have to configure the adapters with priority and seperate IPs and have them BOTH registered in DNS (Active Directory driven DNS that is)