What does "doesn't work" actually mean? What happens when you try?
did you try these links too?
Error "This serial number is not for a qualifying product" | CS6, CS5.5, CS5 >>> Contact Adobe Customer Care for help unlocking your serial number.
If your problem stillresits you should use
http://helpx.adobe.com/contact.html >>> Lightroom >>> http://helpx.adobe.com/contact.html?step=LTRM_downloading-installing-setting-up_licensing- activation and click through the headlinses till the chat is offered (see screenshot):
and if "open" please use chat, I had the best experiences. I quote from Preran: The chat button is activated as soon as there is an agent available to help.