Thanks for your prompt reply Patonb I also felt like that Vista and Win 7 are better then XP that is why I purchased Vista Ultimate. But, I think they are better on papers only and not in day-to-day working. Following are few major problems with Vista and Win 7:-
1) File/Folder Copy is damn slow as compare to XP;
2) Formatting is of great concern as it works like digging tunnel through Himalayas;
3) File Explorer is hard to keep desired settings and keeps changing I do not know why;
4) Vista and Win 7 slows down drastically with time;
5) Most important XP is as simple to understand and use as even kids can handle. But, Vista and Win 7 are big pain. We use application to help us and not for pain;
6) As far as tweaking is concern I fail to understand why we need to do this at all for simple day-to-day working. Do we need to be software expert to use OS? If so, it's better to switch to Unix as it's more powerful and stable system;
7) Vista and Win 7 keeps crashing every now and then. But, yes They have much better GUI but who cares about face if figure is out of shape.
So, my conclusion is XP is reliable and trusted like Wife and Vista and Win 7 are beautiful like Girl Friends.
-Peace