i just installed h100i, had the same issue usb device not recognized, other devices showed up in corsair link software but not h100i unit. so i changed usb mobo connector whilst os was running win 7 and usb driver device re-installed then i updated corsair firmware and walla all showed up fine.. hope this helps if not tried already, make sure do this while os is running seems to the ticket.. mobo is msi z77 mpower