&gt; Vista, despite it being a disaster for Microsoft, was only problematic because of changes made to the UX.<p>The only major regression that comes to mind here is UAC. I don&#x27;t think Vista is considered a failure because of its UX decisions.<p>In my experience, Vista was incredibly slow (compared to XP) and unstable, and got even worse the longer you used it. Anecdotally, even PCs that shipped with Vista were often unable to run it smoothly.<p>I don&#x27;t think Vista would have been a hit with an unchanged Windows XP user interface.