...and before you mod it down, please read it and give it some thought... it'll make sense.
If the truth be known, Windows will never be a completely bug-free and stable OS. Sure, it may come close, but it's never going to be perfect. And this isn't because of the natural human nature of programmers, either. I'm not talking about minor/very small bugs - but rather bugs that are at least rather annoying.
Why? It makes perfect sense as a corporation to release a product that is perpetually "almost there" as far as QA is concerned (especially if they charge for upgrades.) Simply put, if Microsoft can create an image of, "Dangit, we ALMOST had all the bugs out... maybe next time!" to its customers, then those customers are probably going to purchase the next release of Windows in hopes that those bugs are fixed. Of course, fix those bugs, but make sure to add some sort of new stuff (features, eye candy, etc.) that have a few bugs, so that the same cycle repeats itself.
Why woulod they do this? Think about it this way... If WinXP turned out to be a completely stable, bug-free version, and taking into consideration their track record of being rather buggy at times, would you upgrade past WinXP? If you're like a lot of people, probably not. I know several people who have told me already that they are 95% happy with their Win98, and will NOT ugprade past Win98 for fear that the new versions may be buggier. I am sure a lot of people have that same general feeling, and if they ever got their hands on a "good" version, they'd stick with it.
I will give them this much - creating the "Bother, we THOUGHT we had all the bugs out!!! But, we'll get it next time around!" look to all its customers has seemed to keep them on the upgrade track rather well. :) Question is, how long before the customers catch on?