Some third party companies may take their own decision to sell Intel® wireless adapters but Intel intends to distribute them to Original Equipment Manufacturers only. Therefore, the OEM or the seller should be providing the warranty and the party integrating the device is responsible for such integration.
I also noticed you are using a desktop system; in this case we may suggest the Intel® Centrino Wireless-N 2200 for Desktop or Intel® Centrino Advanced-N 6205 for Desktop which are retail products and are expected to work in a desktop computer.