Common Dialog Box Default View

Until recently, when I tried to save a document or image -- say, a pdf
file on the Internet -- a common dialog box would open arranged
alphabetically by name and in list view. Now, when I attempt to save
such a file, it opens in thumbnail view, arranged by date modified and
in descending order. I hate this.

How can I change it back to the original view? Is it a registry setting,
and if so how do I restore the default? Is it a group policy edit? If
so, which one?

I have already tried resetting all of the folders in Windows Explorer to
their original default settings. This didn't work.

Thanks