On a computer that is running Windows Vista or Windows Server 2008, a Peripheral Component Interconnect (PCI) Express interface is available that supports hot-plugging. However, when you hot-unplug a device from the PCI Express interface, the system becomes unresponsive.
Additionally, a CPU internal error (IERR) occurs. If the computer is equipped with an IERR LED, the IERR LED flashes.
Note: An IERR is an unrecoverable internal CPU error. Processors do not execute any instructions until the system restarts.