I should have read reviews and take them into account. Under Win7, in normal mode, the discs (two Seagate 500GB) are recognized from time to time ... And when they are, after a few minutes the system asks to format (with lots of small windows that s 'open and close in time to the recognition of records ...). And assuming that we accept, Windows responds that he can not. I tried maccommoder this big inconvenience. But after one day, return at Amazon for exchange. Exchange I finally canceled. Not want to have unreliable hardware.