Found via PC World: The image to the left is a partial screenshot from Dell's Web site that indicates what qualifies a PC as "Windows Vista Capable"...the ability boot the operating system but not run any applications. From the looks of it, your PC can be marketed as a Vista machine even if it can't run any of the Aero visual elements that are billed as a primary reason for upgrading to Vista in the first place. Imagine the conversations you can have with the intended scenario:
Friend: "How come XP won't let me open Office?"
You: "That's not XP. That's Vista."
Friend: "Cool! How do I make all the app windows go 3-D and hazy?"
You: "Can't. MY PC is only Windows Vista Capable, not Windows Vista Competent."
Short of Ubuntu users, nobody is so in love with an OS to just watch it run in safe mode. Users expect to be able to put a new operating system through its paces...for about 90 minutes, then disable all the bells and whistles to decrease lag in World of Warcraft or Counterstrike. You can't skip the first step, Dell!