Adobe CS5 license key

Hi,

I had Adobe creative suite 5 design premium on my old pc. I deactivated it there in order to install on my new pc.

I have tried to register the license key to my account here in order to download the product but it keeps saying 'This serial number is already in use'

After speaking with Adobe live chat they say "your provided serial number if for CS5 volume license and there is no activation servers available for it to check the details"

Please can someone let me know how to download Adobe creative suite 5 design premium on my new pc and activate it with the serial number.

Thanks