Thought I would update all the people interested in the subject of Pavilion Dv9000. As mentioned previously I installed W7 without any problem. The only hiccup was that M refused to activate my W7 for complicated reasons which I will not waste your time on. I decided the solution was to buy W8 pro and duly installed it. It took a long time (2hours) because of the slowish processor. BUT it is wonderful! The computer is now the fastest it has ever been - I know not why. I think that maybe W8 is much slicker. There are those who criticise W8 but it is seamless and anyone working with computers cannot spend hours trying to rectify networking/internet problems etc.
AlexKoh