No you can't
No. Obviously, if you upgrade to Windows Vista, you will have Windows Vista.
Drivers written for Windows Vista are not backwards-compatible with Windows XP. Most hardware that has a driver for Vista should also have a driver for Windows XP.
There's no such thing. It is not possible to run Windows XP on a Nintendo DSi.
They are "compatible" in the sense that many applications that run on Windows XP will run on Windows Vista.
Yes ofcourse, Windows Vista is upgraded version of Windows XP. Obviously it can run Windows XP applications.
"Vista XP" is not a computer type. Vista and XP are both previous versions of the Windows operating system. The current version of Windows is Windows 8.1.
Windows Vista is notably far more secure than Windows XP.
No.
There is no such thing as "Windows XP Vista." There is Windows XP and there is Windows Vista. They are two different versions of the Windows operating system (XP is older than Vista). As to which is better (XP or Vista) if that is your question -- I think most people would say that XP is better, but this probably depends on which operating system you are used to and what type of work you do with the computer. That said, even Windows Vista is out of date, now. New machines will have Windows 8 (or Windows 7 if it is slightly older).
You cant, windows xp sucks. Windows vista the best! with windows vista you can do it!
Sorry only for Windows 2000 / XP /Windows Vista /Windows 7
No. Due to the length of time between the releases of Windows XP and Windows Vista, as well as Windows Vista ditching support for some legacy technologies, there are many devices that will not function in Windows Vista but work in Windows XP.