I had Windows Vista Ultimate installed on my laptop. I purchased the Windows Vista separately, like a box with media and product key, not with my laptop. I used Windows Vista for nearly one year, I bought a desktop and installed Windows Vista on the desktop as well. It worked without any problem on both my laptop and desktop for nearly 6 months. Now I bought a new laptop and installed Windows Vista on it. It said there is a problem with the activation. So I formated the hadrddisk of my old laptop and installed Windows XP on it. Now I try to activate Windows Vista on my new laptop but I get the message "Producty key already in use". At the moment I have only installed Windows Vista on my desktop. Can you please give any advice how to activate Windows Vista on my laptop?