Thanks for your reply. But are you sure you are using the Thunderbolt Gigabit
Adapter not the USB Megabit Adapter?
I'm sure I installed the latest boot camp (it's still the 2011 version for my MacBook Air
2011). As I know the thunderbolt adapter is also just supported by MacOS whith a update this year, so I don't think it's already supported by boot camp last year.
If you are sure you are using the thunderbolt one correctly in Windows, would you please tell me where you got the latest boot camp? Thanks. I've just downloaded it from boot camp assistant last week and found it's still the 2011 version for my Air.