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Article ID: 327947 - Last Review: June 19, 2014 - Revision: 3.0

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986  ( ) Description of the Microsoft Windows Registry


After you install Windows 2000 with an integrated (slipstreamed) Service Pack 3 (SP3), some 16-bit internal and external PC Card devices devices may stop working correctly. PC Card devices are also known as Personal Computer Memory Card International Association (PCMCIA) devices.


This behavior may occur when the IRQ of your PC Card device is not routed correctly. The following devices are frequently affected by this symptom:
  • Integrated wireless network adapters that are based on PC Card standards.
  • Devices that are used in PC Card slots in desktop computers.
All of these devices require PCI routing. By default, Windows 2000 SP3 turns off PCMCIA-to-PCI IRQ routing.


WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To turn on IRQ routing when you are using Windows 2000 SP3, edit the registry. To do so, start Registry Editor, and then view the following key in the registry:
Add the following registry value to this registry key, and then quit Registry Editor:
Value name: DisableIsaToPciRouting
Data type: DWORD
Value data: 0

More information

This symptom may occur with the Lucent/Orinoco 802.1x wireless network adapter. After you install this adapter, the network appears to be available and the signal strength remains the same. However, the network is unavailable, and the network connection icon has a red "X" over it.
kbenv kbnetwork kbprb KB327947
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