What is the model number pls? WPA4220KIT? Yur tried the password of your main router. How about the 8-digit password printed on the back of powerline extender? If neither work, try to find it out on...

Exit the utility. Disable anti-virus software and firewall. Run the utility again to see if it helps. If no, you may try a different computer. By the way, are you running the utility for PA4010 or...

Run the utility for WPA4220 and login its web interface to check if SSID and security settings are the same as your main router. http://www.tp-link.com/en/download/TL-WPA4220_V1.html#Utility You can...

If you connect the PC to your router directly as other devices, can you ping or access to your PC from any of other devices? Disable anti-virus software and firewall on your PC. Powerline devices...

Download the utility here and run it on your PC. http://www.tp-link.com/en/download/TL-WPA281_V1.html

If the card is not in the list, I'm afraid that TP-LINK has no any update plan for it...:(