What do windows "interface names" look like?

There's also if_indextoname. I've added the output below. This style of name (e.g. loopback_0) is not the Win32 interface name. I guess these names only exist for compatibility with rfc2553. Win32 actually uses interface names like \DEVICE\TCPIP_{846EE342-7039-11DE-9D20-806E6F6E6963}.

To enumerate all the interfaces you need to use GetIfTable and friends. if_nameindex is not supported.

loopback_0
tunnel_0
tunnel_2
tunnel_3
ppp_0
ethernet_0
ethernet_1
ethernet_4
ppp_1
wireless_0
ethernet_9
tunnel_4
tunnel_1
tunnel_7
tunnel_8
wireless_5
tunnel_5
tunnel_9
tunnel_10
tunnel_6
wireless_1
wireless_2
ethernet_2
ethernet_3
ethernet_5
ethernet_6
ethernet_7
wireless_3
wireless_4
wireless_6
wireless_7
wireless_8

They look like \Device\NPF_{506B4345-1FC0-43F4-BFCF-4FFAD7739AFF}. I don't know if there's a more direct way to get a list of interfaces, but I got this one from wireshark, which uses winpcap.