Take a look at the graph concerning OS. I do not claim it is 100% accurate, it gives a good idea on how bad Vista did. Vista never got above 25%. It would not have gotten that far if M$ had not made the puter manufactures install it and then allow the user to upgrade to XP. ( I say upgrade because so many of us think Vista never got close to being as good as XP.) It was not until sp2 did Vista begin to even begin to work properly. Pay attention to how fast Win 7 blows Vista away. It takes less then a year for it to surpass Vista. Also remember that PC sells fell close to 25% while Vista was the main stay for the PC manufactures. That is why Win 7 was rushed to market.
Will we see a repeat while Win 8 is M$ main OS and will Win 9 be rushed to market to keep the PC from dying. The one good piece of good news I am hearing, have yet to confirm it, is that PC manufacturers are going to be allowed to sell Win 7 on business systems while Win 8 is sold on home system.