AeroGlass for Windows 8.1 seems to work nicely on two monitors. But there is a difference to the Windows 8 version. It does not work on a three monitor configuration. Both 1600x1200 monitors are working fine with AeroGlass but the third (1280x1024 rotated) is not able to display anything. Not that it is black, it shows a little part of the desktop but when a window is moved to this monitor it is not displayed. If it helps, the third monitor is connected to the second graphic card. Both cards are nVidia and I am using the latest nVidia drivers.