It is great that it works fine now. it was free help;)

you can refer to the compatibility list: http://www.tp-link.com/resources/document/TL-WPS510U_Compatibility_List_.pdf

You can try to uncheck Enable WMM on the Wireless Advanced and change the channel on the Wireless Settings.

1 unplug the other two adapters from the socket 2 unplug the new one, and only plug the new one back to the socket. the other two are still unplugged. and try again to see if you can login to...

Superduper97 , so when you connect the laptop to the powerline unit, the internet works fine; when you connect the desktop, you can not connect to the internet? 1. When you go to network and sharing...

1 unplug the other two adapters from the socket 2 unplug the third one, and plug it back to the socket. and try again to see if you can login to 192.168.1.1 or not. 3 if not, try to reset it.