I already had a pair of the PA-211 adaptors, to speed up the connection between my Virgin-supplied router (which is next to the TV) and my desktop (on the floor above), but wanted to boost the wireless signal to another corner of the house.
I followed the instructions that came with the extender, which said you should connect it to the computer and pair it with the adaptor connected with the router, but really struggled to get them to pair. This also meant that the internet connection to the desktop went on the blink, messing up my attempts to configure the extender. I am not particularly tech-minded, and found the instructions, both on-screen and on paper, less than enlightening. After hours of rebooting and running up and down the stairs, I gave up, and went back to the two adaptors.
A week later I decided to have another go, and finally it worked. The secret, it seems, is to switch off the wireless signal on the extender while you get the Powerline connections established. I now have a fast connection between my router and desktop, and a strong wireless signal where I need it for my iPod Touch (used to control Sonos wireless music system), and smartphone. I also have several more grey hairs.