Using ThunderBolt 27" Display with a Second VGA Display not working in Bootcamp
Yo.  I've tried with every possible scenario.  I found a note on Apple's site somewhere that stated that only one tb monitor is allowed for use in windows 7.  So...  Until they update the drivers for Win7 you can't get it working.  However...  If you use a TB Imac and add a second monitor to it, that does work as I have that setup at home.