Cisco Aironet WLAN Client Adapters Tools For Systems Administrators

Cisco Aironet Driver and Firmware FAQ

Document ID: 7278

Updated: Jul 10, 2009



This document answers frequently asked questions (FAQ) about the Cisco Aironet Driver and Firmware.


  • Cisco Aironet Client Adapter cards have driver support for Microsoft operating systems. This document makes reference to MS-DOS and Windows operating systems. Cisco engineers do not support these operating systems, except as the systems relate to the client adapter card drivers and the Aironet Client Utility (ACU).

  • Cisco recommends that you have knowledge of Interrupt Request (IRQ) settings and the Device Manager concepts in order to effectively use this document.

  • Cisco Technical Support recommends that you have the latest software and firmware before you create a service request.

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Get New Drivers and Firmware

Q. What are the different types of wireless cards available from Cisco?

A. You can download the latest firmware and drivers for wireless products from the Downloads - Wireless ( registered customers only) page. To download the software for a device go to corresponding major product sub-section from Downloads page. Then click on the specific product and download the appropriate firmware or utility.

Q. Where can I get updated drivers and firmware?

A. You can download the latest firmware and drivers for wireless products from the Downloads - Wireless ( registered customers only) page. To download the software for a device go to corresponding major product sub-section from Downloads page. Then click on the specific product and download the appropriate firmware or utility.

Drivers—PCI and PC Card

Q. How can I reload the drivers for the Protocol Control Information (PCI) card after I have removed them?

A. Uninstall the PCI card and locate the pcx500.sys and vxdx500.vxd files in the C:\Windows\system directory. Delete both files, and then reinstall the drivers.

Q. I have a Cisco Aironet PC card. Why does a yellow "!" appear in the Windows Device Manager?

A. This symbol indicates that drivers are not installed properly for the card. You must reconfigure the PC card. Complete these steps:

  1. Remove the PC card and reboot.
  2. Once the system is operational, remove all instances of the PC card from the Device Manager and reboot the system again.
  3. Reinstall the latest drivers for the card. In order to download software for a PC card, go to Wireless Software from the Cisco Downloads ( registered customers only) page. Navigate to Client Adapters and Client Software. Choose the desired Client Adapter and download the appropriate firmware or drivers.

Q. How can I get the Aironet PC card drivers to load in a system with multiple PC card devices?

A. Complete these steps:

  1. Disable previously installed PC cards.
  2. Install the Aironet wireless card.
  3. Then renable the remaining PC cards.

    Note: Even during wireless access it is recommended to disable other cards to avoid conflicts.

Q. I have a Protocol Control Information (PCI) client adapter card. Why does the PC freeze or hang when I load the driver and reboot the PC but work normally if I remove the card?

A. An Interrupt Request (IRQ) conflict causes this problem. Uninstall the PCI card (including drivers and firmware) and check if the conflict arises. Insert the card in a different slot and reinstall the drivers.

Q. Why does Windows 2000 produce this error message: "The form specified is not one known and recognized"?

A. This error is security-related. Run the Microsoft Management Console (MMC) and load the Security Configuration tool. Choose the option that installs unsigned device drivers.

Q. After the Aironet card is installed the PC freezes or hangs when Windows restarts, and the PC is not able to boot to Safe Mode. What can I do?

A. Windows 98SE/ME uses the Advanced Configuration and Power Interface (ACPI) for Interrupt Request (IRQ) steering and tries to place all Protocol Control Information (PCI) devices on the same IRQ. Windows 2000 behaves in a similar manner. In order to avoid this occurrence, try one of these methods:

  • Install the card in the slot closest to the CPU.

  • Remove all Aironet-related files and drivers and reinstall them. Be sure to complete all of these steps:

    1. Remove all files, drivers, and anything Aironet-related.

      This includes pcx500.sys, vxdx500.vxd, all .inf files, any files with the name aironet*.*, and any netx500.* files that exist in the C:\Windows directory or its subdirectories.

    2. Remove Aironet-related items and devices from the Network Adapters in Device Manager.

    3. Reinstall the drivers.

  • Use the Device Manager to change the IRQ settings for Aironet. Be sure to complete all of these steps:

    1. Choose the Aironet item under Network Adapters.

    2. Click the Resources tab and uncheck the Use Automatic Settings check box.

    3. Enter the correct IRQ setting for your system.

  • Disable IRQ steering on the PCI Bus. Be sure to complete all of these steps:

    1. If your system shows the PCI Bus in the Device Manager, double-click PCI Bus.

    2. Click the IRQ Steering tab and uncheck the Use IRQ Steering check box.

      This action disables IRQ steering.

    3. When you are prompted in the display window, click OK, click Next, and click OK.

    4. Click Yes when you are prompted to restart your system.

Q. I use Wired Equivalent Privacy (WEP) and I cannot upgrade the firmware for the Protocol Control Information (PCI) card. What can I do?

A. Remove the WEP keys and then upgrade the firmware. Then uninstall and reload the new driver. You can also use the RMWEPv1.0.exe file from the Cisco Aironet Windows Utilities site to remove the WEP key automatically.

Q. Can I change Aironet card settings from the Linux command line?

A. Cisco does not offer command-line parameters for any of the available drivers, including Microsoft and Mac OS. All client setup is done in either the ACU or through the Network Control Panel in Windows.

Q. I have multiple access points and need an easier way to change the Wired Equivalent Privacy (WEP) keys on the units. Can I change the WEP keys through Simple Network Management Protocol (SNMP)?

A. Unfortunately, you cannot change the WEP keys via SNMP because only one variable can be written at a time using SNMP "puts" operation. Whereas WEP requires two variables such as WEP key and the key length to be written to the radio at the same time.

Q. I have some AIR-PCM340 client adapter cards that get 100 percent signal quality and work without problem. I also have some AIR-PCM350s that only get 70 to 80 percent signal quality when they are installed in the same machines and are the same distance away. Why?

A. Some versions of firmware actually change the readings. Inside the card, an analog-to-digital conversion takes place. The analog reading that the card gets and reports to ACU does not always use the same calibration that was used in some of the earlier versions of firmware.

In order to get a more accurate reading in later versions, a change in the way that analog signal interpretation occurs was necessary. Therefore, when you change firmware versions or look at earlier cards and compare them with later cards, the readings on the later cards can appear to be lower.

Start ACU and perform a status on the different cards. Is the firmware the same on both cards? If the firmware is not the same, is there a later version of firmware available for the card that has the higher reading? If there is a later version, flash the card with the updated firmware. The reading should drop and become closer in value to the card that you suspect to have a problem, especially if the suspect card is a later version.

Each radio card is slightly different because of component tolerances. You can test five radios and get five slightly different readings, although the readings are nearly identical.

You can try another approach. Browse into the access point and see how the statistics for both cards compare. The access point is the best reference to determine which card, if either, is better.

Q. Do some combinations of the firmware and utilities work better than other combinations?

A. Use the most current firmware and drivers from the Wireless LAN Access section of Downloads - Wireless ( registered customers only) .

Q. Are there drivers for the DOS operating system for Aironet Cards?

A. Currently, DOS drivers are present only for Cisco Aironet for Cisco Aironet 350 Wireless LAN Client Adapters. In order to download the software, go to the Wireless Software page from the Download Software link. Click Client Adapters and Client Software. Navigate to Cisco Aironet Wireless LAN Adapters, choose Cisco Aironet 350 Wireless LAN Client Adapter and download the drivers from Aironet Client Firmware.

Q. The DOS 340 Access Point series download appears to have drivers for the 4800 instead of the 340. Is this right?

A. The 4800B and the 340 are the same hardware. The 340 Access Point DOS drivers work with the 4800B.

Firmware—Access Points and Client Adapters

Q. The access point does not accept the new firmware that I have downloaded. Why?

A. Make sure the .exe or .zip file that you downloaded is uncompressed before you attempt to load the firmware. The hardware does not accept compressed files.

Q. When I try to upgrade radio firmware, the download stops at partial load, and this error message displays: "Error writing to Flash". Why?

A. Disable the radio port before you run the upgrade process. Use the ACU command menu selection for radio off. If disablement of the radio port fails, use the latest version of the ACU.

Q. When I upgrade my access point firmware, this error message displays: "Bad File Format". Why?

A. There is a possibility that the firmware upgrade file is corrupt. Download the file again and, rather than overwrite the original file, extract the file to a different directory.

Q. Does the ACU support Wi-Fi Protected Access Pre-Shared Key (WPA-PSK)?

A. WPA provides a Pre-Shared Key version (WPA-PSK) that is intended for use in small office, home office (SOHO) or home wireless networks. ACU does not support WPA-PSK. The Wireless Zero Configuration utility from Windows supports WPA-PSK for most wireless cards.

Q. Does ACU support Extensible Authentication Protocol-Flexible Authentication via Secure Tunneling (EAP-FAST)?

A. Yes, EAP-FAST is supported in ACU version 6.3. Also, EAP-FAST is a Cisco Compatible Extension (CCX) version 3 attribute. Therefore, this will be supported only in third party devices that have passed the CCX V3 compliance test. Refer to the Cisco Compatible Client Devices matrix for more information on CCX.

Q. Drivers for the Wireless client card display the error code : 12. What does this indicate?

A. One reason for this error message is because the device in question might not find enough free resources that it can use. If you want to use this device, you will need to disable one of the other devices on this system. (Code 12).

Refer to the article Code 12: This device cannot find enough free resources that it can use for more information.

Related Information

Updated: Jul 10, 2009
Document ID: 7278