While Microsoft Windows 7 is the mainstream Windows OS in use now, people still prefer and use Windows XP. I recently came across an Windows XP specific issue, where the computer detected security enabled WiFi networks but failed to connect with them as shown below.

As evident from the error message above and pretty descriptive error-icon shown below, Windows XP SP2 is having issues trying to negotiate security certificate. To fix this, enabling WPA and WPA2 encryption support on Windows XP in Wireless Group Policy (WGP) we need to install KB917021 update from Microsoft.