Personally, I don't think that any OS is even close to being what Windows is. Maybe Macs are the closest and I believe they got a few things down better than Windows, but this alternative isn't free either. As for Linux I have tried different linux OSes and I see only use for them in server environments. None of them have made me want to lose Windows completely because they weren't as plug and play as Windows is.
Another killer point for Microsoft is the whole Visual Studio environment and the .NET language. I haven't found a single IDE that is as powerful as Visual Studio and the language (C# notably, but also any other .net language) is also by far my favorite language. Compared to Java, I know that the language isn't that much different, but because Visual Studio makes it so easy, so plug and play, it gives you the freedom to concentrate only on the code and nothing else. I've had bad experiences where IDEs made from Java for writing Java software are really slow and buggy, and that's not what I've seen so far from software written in .Net either as free or paid softwares.