Boot Camp only detects two out of three monitors Setup: brand new MacBook Pro with Retina Display plus two 27" Thunderbolt displays. So, three displays in total, which works like a charm in OS X.

Unfortunately, when boot-camping into Windows 8.1, it detects only two of these: the one on the MacBook and the (first) external one:



Note that interestingly, the devices plugged into the secondary external monitor still work - e.g. all three cameras are there.

Any ideas?
From http://support.apple.com/en-us/HT204154


How many Apple Thunderbolt Displays can I use with a Mac in Windows 7 or 8 with Boot Camp?  
Most Mac computers can support one Thunderbolt display using Windows. The iMac (Retina 5K, 27-inch, Late 2014) and Mac mini (Late 2014) can support two, and the Mac Pro (Late 2013) can support up to six.