According to PC World the biggest disappointment of 2007 was.... VISTA!
It's just that Vista isn't all that good. Many of the innovations the operating system was supposed to bring--like more efficient file and communications systems--got tossed overboard as Microsoft struggled to get the OS out the door, some three years after it was first promised. Despite its hefty hardware requirements, Vista is slower than XP.
To be fair, that's something that you should normally expect from any new Operating System. If you keep adding new more complex objects and animations into the OS it will become slower at some point. But that's not the main issue here. The complains come from the fact that Vista is 5 or more times slower than XP.
Now, that's the first disappointment of 2007 according to PC World - a magazine that I do not like too much, I should add. I'm gonna tell you now the 2nd big disappointment of 2007 according to me. It's..... ta da da... Zune Software! I never have seen a 2nd version with less features than the previous one. In my mind, I have embedded something that says that a Second Version of any software is or should be better and keep the features that everybody likes from the first version. Well, that's not the case with Zune software where everything that was useful and popular from the first version was removed in the second one.