This is due to the existence of a security hole in Universal Plug and Play (UPnP). When abused, there is a possibility of an external person performing a wicked code, capturing a network, or devising a service refusal (DoS) attack. Since the UPnP function is effective by default, a patch needs to be applied to Windows® XP immediately. Users of Windows® 98/98 Second Edition/Me needs the patch only when the UPnP function is being used.
The patch for this symptom is available in Microsoft's website. Click here to download.