It's done through Sony's SEN website now
Go to http://www.sonyentertainmentnetwork.com/gb-en/home
Then click the 'Devices' tab, followed by 'PlayStation Systems'
If you've activated your console it should already appear here anyway
thanks a lot for the reply, but how can I check which PS3 is activated in my account?
you see the thinbg is I had PS3 Slim and changed it for PS3 Super Slim, but before selling my old one I deactivated it(on PS itself) and activated my new one but I just want to make sure it all worked fine, that is all and in my account under Devices it just says "My PS3 System"