PCI Express or ExpressCard device appears connected after being hot-unplugged


If you have a hot-pluggable PCI Express or ExpressCard device installed in a computer running Microsoft Windows Vista, and then remove (hot-unplug) the device, there is no indication that the device has been removed. For example, the device may continue to appear in Device Manager. Choosing the "Scan for hardware changes" action in Device Manager allows the device removal to be detected, in which case the device no longer appears in Device Manager.


This problem may occur on Windows Vista if the hot-pluggable PCI Express or ExpressCard device is installed in a slot provided by certain PCI bridges which signal the device-removal event in an unexpected way.

The Windows Vista PCI bus driver (PCI.SYS) expects certain PCI Express/ExpressCard hot-plug events to occur together, such as SlotEventEnableRequest & SlotEventLinkStateActive, or SlotEventSurpriseDisableRequest & SlotEventLinkStateNotActive. Some PCI Express bridges do not signal these events together at the same time, with the result that the Windows Vista PCI bus driver does not successfully process these PCI hot-unplug events.


This problem is resolved in Windows Vista Service Pack 2 (SP2) and Windows Server 2008 SP2.

Article ID: 2470260 - Last Review: Nov 24, 2010 - Revision: 1

Windows Vista Ultimate, Windows Vista Enterprise, Windows Vista Business, Windows Vista Home Premium, Windows Vista Home Basic, Windows Vista Starter