This is an interesting little problem. On one of my computers, it normally supports 9 monitors. 6 monitors on 3 PCIeX16 dual VGA/DVI cards. And the 3 extra monitors by some SIIG USB-to-VGA Pro adapters. A strange thing happened yesterday. Everything was working okay - all 9 monitors were okay... until... Rebooted the box. After reboot, 2 of the monitors no longer get displays. But the symptoms seemed strange. Let's say: Monitor 1, 2, 3, 4, 5, 6 are hooked up directly to the PCIeX16 cards, and monitor 7, 8, 9 are hooked up via USB-to-VGA adapters. When I unplugged all 3 USB-to-VGA adapters, monitor 1 through 6 all worked fine. As soon as I plugged in even one of the 3 extra monitors via USB, monitor 1 and 2 no longer got display. So I could have monitors 3, 4, 5, 6, and 7, 8, 9 (all 7 monitors total). 1 and 2 just wouldn't come on in conjunction with any of 7, 8 or 9. When I unplugged the USB-to-VGA adapters and un-installed the DisplayLink app (driver), monitor 1 and 2 worked fine again and I have a total of 6 monitors all through the PCIeX16 cards. During boot up, BIOS does complain that "CPU overheat, press F1 to continue". But the computer still runs okay, it seems. It seems as if the CPU overheating is affecting the onboard USB interface, and some of the cards on the PCIeX16 bus? Is it possible? I will get a heavy duty CPU heat sink to deal with the CPU overheat error. I hope it will resolve my USB display issue too. If anybody has seen similar strange problem, I appreciate some suggestions. Thank you!