Just registered to say thank you to smurphboy.
I wanted my brand new Picade to run a x86 based computer to get more power than the rpi2, especially to get latest Mame versions and also emulators that won't run on my rpi2 (Dolphin, PCSX2,...). I'm running Windows 7 x64 on a i5 Broadwell NUC for my tests. Installed the picade.inf driver available at github and the board get recognized immediately. Sound +/- working, but no way to get the other buttons and the stick to work. Tried everything like flashing the other firmwares (gamepad and 2016 lastest), but no way to get those damn controls to work in Windows. Game controller panel even showed a 3axis 16 buttons device with those firmwares, but no way to get any input from the stick, even in the test dialog with this device selected. Then I removed the picade.inf drivers from github and declared the board as an USB composite device like smurphboy did. MIRACLE !!! Everything is now working fine.
Will certainly post a full report in a couple of week after everything will be fully installed and configured the way I want it (Sanwa joystick and buttons, 12" screen replacement, miniITX board and CPU also ordered).