I bought Windows 7 Professional so I could put it on my penultimate MacBook (to view CD discs of encrypted x-ray images that can't be opened in OSX). The laptop has a disc driver and this version came on a disc with the activation code. I installed it using Bootcamp, a USB stick to record the temporary files off the internet from Apple and a video on Youtube (the top hit for this exact activity). The video showed him unticking "register automatically with Microsoft using the internet". A good move. It all went perfectly (I'm far from nerd) and it now runs nicely. For £17 I have exactly what I wanted. Thank you very much! Professor Peter Thomas