Since Flash 10, the upgrade experience is fairly streamlined, but the dialogs that appear have tripped me up on multiple occasions.  And yes, I stress multiple, because they have a point release every week it seems, and with my 3 virtual machines plus main machine I went through a stretch a few months ago that I felt like I was completing the upgrade wizard every day.  Finally I decided to save the steps and write about it because I feel it is so obviously confusing, and yet if you only go through the process once or maybe twice every few months you probably think nothing of it.

Here is the first dialog that pops after booting up Windows:

Now after clicking "Install" you get a loading progress bar as the new version downloads.  Then you get this dialog:

Notice anything similar?  For one, there's that same "Install" button in the lower right.. didn't I just click that? Why aren't you installed yet?  That's the first problem.  How about just do the install when I said so the first time.  But wait, there's more.  On the first dialog, the single checkbox was to stop reminding me about this update.  But when I proceed now I'm seeing a similar dialog, with similar calls to action, so my brain instinctively ignores the checkbox.  Try to click Install this time and you get a warning message that you didn't agree to the terms. Doh!

This is what I end up seeing for both dialogs: