Why Windows XP?

Well, as you may know i am running windows xp and have no reason to upgrade to Windows Vista or Windows 7. Why may you ask? Well although windows vista has very good security, its features are not as stable as windows xp. There are also more features in Windows Vista or Windows 7, but seriously. An operating system that uses 1 GB of RAM and takes up 15 GB of space?? Where as windows XP takes up 3GB of space and uses very little RAM. That's why i use Windows XP