Many XP with SP2 wireless issues can be fixed by
installing MS Hotfix
Case 1: The XP computer doesn't have option to select WPA2.
Case 2: You can receive strong wireless signal but not connection.
Resolution: Downtown this hotfix:
Description of the Wireless Client Update for Windows XP with Service Pack 2
The Wi-Fi Protected Access 2 (WPA2)/Wireless Provisioning Services
Information Element (WPS IE) update for Windows XP with Service Pack 2 is
Case 3: You have a USB-based wireless connection enabled on a computer that is running Windows XP or Windows Vista. Even when there are five or more wireless network connections available, the Wireless Network Connection dialog box shows that there are a maximum of four wireless network connections available.
Resolution: download and install this
hotfix: You see only four available wireless network connections when you
use a USB-based wireless network adapter in Windows XP or in Windows Vista
Case 4: After you install Microsoft Windows XP Service Pack 2 (SP2), your Protected Extensible Authentication Protocol (PEAP) connection does not authenticate successfully. This failure occurs during an authentication attempt to a third-party Remote Authentication Dial-In User Service (RADIUS) server.
Resolution: Download and install this
hotfix: PEAP authentication is not successful when you connect to a
third-party RADIUS server.