Hello,
No, I don't have usb adapter, network card is onboard-motherboard.
I already checked ram with Memtest for 24 hours without problems.
Actually I've disconnect my mechanical HDD (I've just one SATA disk).
My full specs:
Enermax Infiniti 720W :: Q6600 step g0 :: Nirvana NV120 :: XFX 790i Ultra BIOS P09 :: 8GB CORSAIR DDR3 1333MHz :: GTX 460 XLR8 :: Zalman ZM-MFC2
Thanks