On Friday, Microsoft gave computer makers a six-month extension for offering Windows XP on newly-shipped PCs. While this doesn’t impact enterprise IT — because volume licensing agreements will allow IT to keep installing Windows XP for many years to come — the move is another symbolic nail in Vista’s coffin.

IT departments are largely ignoring Vista. In June (18 months after Vista’s launch), Forrester Research reported that just 8.8% of enterprise PCs worldwide were running Vista. Meanwhile, Microsoft appears to have put Windows 7 on an accelerated schedule that could see it released in 2010.

So how did Vista get left holding the bag? Let’s look at the five most important reasons why Vista failed.

5. Apple successfully demonized Vista

Apple’s clever I’m a Mac ads have successfully driven home the perception that Windows Vista is buggy, boring, and difficult to use. After taking two years of merciless pummeling from Apple, Microsoft recently responded with it’s I’m a PC campaign in order to defend the honor of Windows. This will likely restore some mojo to the PC and Windows brands overall, but it’s too late to save Vista’s perception as a dud.

4. Windows XP is too entrenched

More Here

Also:

Vista is awful. Everyone knows it, including Microsoft, and now Microsoft’s actions have made it clear that Vista is on its way to the Microsoft junkyard with such similar failures as Windows ME and Microsoft Bob.

You don’t have to believe me. Just look at what Microsoft has been doing. First, Microsoft started fast-tracking Vista’s successor, Windows 7. Recently, we discovered that Windows 7 alpha will be coming to developers this October.

Still, you might think, “So what, Microsoft is still giving us a choice between Vista and Vista for the next year or two.” Wrong. The rumors were true. Microsoft is extending XP’s sales life again.

Rest Here