After you install the Wi-Fi Protected Access (WPA) update (815485) on a Windows XP-based computer, your wireless network adapter may not be able to connect to your wireless access point by using a Wired Equivalent Privacy (WEP) key. When this problem occurs, the wireless network connection status indicates "Wireless Connection cannot be used."
For more information about the WPA update, click the following article number to view the article in the Microsoft Knowledge Base:
815485 Overview of the Wi-Fi Protected Access (WPA) security update in Windows XP
This problem may occur if your computer uses an Intel PRO/Wireless 2100 LAN MiniPCI network adapter with version 126.96.36.199 (or earlier) drivers for wireless access.
To resolve this problem, update the drivers for your wireless network adapter to version 188.8.131.52 or later. For additional information about updated network adapter drivers, visit the following Intel Technical Support Web site:
Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.
To work around this problem, remove the WPA update:
Click Start, click Control Panel, and then double-click Add or Remove Programs.
Click Windows XP Hotfix (SP2) Q815485, and then click Remove.
You may receive an error message that states that some programs on the computer may not work correctly if the update is removed. Click Yes to remove the update.