why windows vista coudn't be as phenomenol success for Microsoft as windows xp?  

i prefer windows 7 above the both since its a mix of windws vista and xp. Xp is use friendly indeed and better suited for simple home users. However vista is a better quality system with better security therefor also a lot more complicated to work with. Windows 7 on the other hand is a mix of both the quality of vista and the simple use of XP. Vista also has a welknown problem of software thats not compatible like games that used to work on XP no longer work on vista. Most of this problem is solved in windows 7 I do however like the grapics from vista the more what 3d stuff and ofc u can put more memory in it XP only goes up to like 3-4 GB wich is for online gameing these days way to less.

XP was so successful because Windows 98 needed fixing. With its endless crashes on a twice daily basis win 98 was crying out for a replacement.
XP was never broken, it did not need fixing, so Vista and Windows 7 were/are only sold om new machines. Both Vista and Windows 7 are just cynical attempts by Microsoft to milk their customers for more money.
There are millions of XP users who see no reason whatsoever to "upgrade" to more modern operating systems. The cosmetic interface differences just irritate many people. Even the Windows 98 interface worked perfectly. I have my XP set up to the Classic (Windows 98) View.

Windows vista was a failure because it had lots of bugs which kept making the operating system freeze and windows vista wasn't fully user friendly as it did not support many hardware drivers and its interface was new and confusing for some people.

due to its heavy and unnecessary program and options.. and moreover fr its sluggish performance