Why slaide? I'll tell you why.
1. Windows what the first user-friendly GUI OS (shhh DOS lovers) in which had a good platform for both games and word-procesing.
2. Being the humans which we are, when we have found somthing we like, trust, and which is easy, we naturaly stick to it.
3. Programer/Devloper: Hmm... since the public like Windows lets make windows based programs, because it would be stupid for us to write a program for another os that has only 1% of PC users. - you see they are only thinking of $$$
4. Microsoft is smart, it releases software which is buggy, then they fix it to show the world that they are good people, and that you can rely on then to fix their software.
Excuse the spelling mistakes, but im tired!!