Ty for reply. Yes lastest bios.
There is probably something wrong is my bios conf.
I'm trying to plug those 2x 290x on a Asus Rog Maximus VII Hero (on PCI-E 3.0 x16) with a 1600W brand new PSU.
Not working as well Oo
Windows crashes on startup (during flag u know) and same 'b2' code on motherboard.
Can't find anything relevant about 'b2'
Regards
Disable everything you don't need in bios. Gaming mobos normally have quite a lot to disable.
This sounds stupid but if there is a bios reset SWITCH, try it, remove battery.
-edit- and if that thing lets you boot to windows, download ddu, boot to safe mode and run that ddu. After that boot normally back to windows and install 15.12 drivers.