When I discussed the behavior of Windows XP SP2's autoplay dialog, one person suggested making the CD autoplay configuration dialog more discoverable to solve the problem of people not knowing how to get back to the dialog to change the settings later.
But what is the boundary between discoverability and annoying behavior?
Windows 95 drew a bouncy arrow pointing to the Start button to draw your attention to it, because usability testing revealed that it wasn't discoverable enough. Yet there existed a population of people who found the arrow downright annoying. And this even though it only appeared once; the moment you clicked on the Start button, the arrow went away forever. But for those people, apparently, even once is annoying.
The autoplay configuration dialog is in a somewhat intuitive place: It's a property on the CD drive itself. Though apparently it's not intuitive enough for some. Even the ultra-geeky Tweak UI PowerToy tells you this. Then again, maybe ultra-geeks are too cool to use Tweak UI.
The fact that many people don't realize where the autoplay configuration settings are kept could mean one of several things. First, it might mean that the location is still not discoverable enough. But configurating one's autoplay settings is hardly a common activity. Do you really want a balloon to pop up each time a CD autoplays saying "Click here to change your autoplay settings"? What if your default autoplay action was "do nothing"? Do you want a balloon to pop up saying "See, I'm not doing anything, just like you told me"? Moreover, if the CD you inserted launches a fullscreen game, the balloon won't be visible anyway, rendering the entire exercise moot.
Another possible reason why people don't find the CD autoplay configuration dialog is that it doesn't even occur to them that this is a configurable behavior; they simply don't even realize that the dialog exists. If you don't know that something exists, you certainly won't go looking for it. (This is why it is often said that a significant part of the scientific research process is merely asking the right question.)
Identifying this boundary and knowing when you've crossed is a hard thing to figure out. If you ask ten people, you will get ten different answers. The ability to strike a balance is one of those things you just develop a sense of from experience, supported by years of usability research.