I just installed Wireshark on Win7 on a Thinkpad. Why is the wireless interface not listed?

On Windows, Wireless adaptes show up as "Microsoft". Please check the IP address of the adapter to identify it.

Wireshark 1.8

Capture -> Interfaces -> "Column IP"

You can also click the Details Button. It will show interface parameters. The Link Speed will be 54 Mbit/s or any other speed specific to wifi, but not 10,100,1000 MBit/s.

Dumpcap will also show the IP address.

dumpcap -D -M

Regards
Kurt