Well xp is made up of 98, ME and 200 am i correct?
Ummm... not really. Some of them are newer versions of the Windows family, but none of them are really "made up of" each other. Let me see if I can explain this.... I know some will take exception to what I'm about to say, but this is it in a nutshell.

Since the early 90s, Microsoft operating systems have been developing along 2 parallel paths. One the one hand, you have the consumer line that traces its roots back to DOS and includes Windows 3.1, 95, 98, and Me. These were basically graphical shells that ran on top of DOS (see my post above), although their exact relationship with DOS was somewhat complex. Microsoft chose to build its 32-bit Windows 95 line on top of 16-bit DOS to maintain backward compatibility with older applications, especially games. What you ended up with was a hybrid 16/32 bit system that was quite frankly an unstable mess, but that had very good backward compatibility. Because of its compatibility with games, it was marketed toward the home user where stability wasn't considered to be that important.

The problem was everybody knew that this architecture was a mess and people were sick of these things crashing all over the place, so Microsoft went to great lengths to try and hide the DOS underpinnings from users for PR reasons. In fact, they flat out lied about it. Windows95 and Windows Me were both marketed as "no more DOS", when in fact all they did was throw up a pretty splash screen to cover up the DOS boot sequence and set the Windows shell to start automatically. While the Windows boot splash screen is up, you can hit <Escape> and just watch the DOS commands roll by..... by the time of Windows Me, they took it a step further and removed the icon for the command prompt and the "Restart in DOS mode" option fron the shutdown menu. But nothing changed. All they did was remove a couple of icons so people wouldn't know they were there. If you want a command prompt in Windows Me all you have to do is open the "Run" dialog box and enter "cmd" or do what I said in my earlier post.

Then on the other hand, you have the corporate line of Windows that goes back to Windows NT and and includes Windows 2000. NT was developed in the early 90s from Microsoft's involvement with IBM and OS/2, and it was written from the ground up as a 32-bit operating system. There was no DOS anywhere in there, and because you didn't have the hybrid 16/32 bit architecture, it was very stable in comparison to the other line. The problem was that because it didn't have DOS underpinnings, backward compatibility with older applications and games sucked. So it was marketed toward the corporate segment where stability was important and people weren't supposed to be playing games anyway..... at least in theory.

The problem was that it was very expensive and impractical for Microsoft to develop and maintain two completely different lines of Windows, and it was very confusing for consumers who didn't understand the difference between them. Windows XP represents the merging of these two lines. It is a consumer-oriented Windows, but it is based on the NT/2000 kernel for stability. The DOS-based Windows line is dead now after WinMe.

There, did you get all that? Clear as mud now?

Dang, I need a beer now......

[edit]
Windows ME is just Windows 98 with 16 bit DOS completely removed.
No, no, no..... I hate to keep disagreeing with you, but this is WRONG. You have bought into the Microsoft marketing hype. There is NO DIFFERENCE between Windows 95, 98, and Me as far as DOS goes. All they did was remove the option to exit the shell from the shutdown menu to try and fool people.