[dba-Tech] Detecting the default browser

I am in the process of downloading the latest beta of a product that I use.
(I won't name it.)  What puzzles me is that when I receive notifications
that a new build is available for download, and click on the URLs to
download the files, MS Internet Explorer is invoked, rather than Chrome,
which is already open! There must be some simple way to detect what I've
identified as my default browser; after all, every rare time that Internet
Explorer is invoked, it can tell it's not my default -- it asks me every
time whether I'd like to make it the default! So why can't other software
vendors do the same? I also occasionally run FireFox, and it too notes that
it is not my default browser

This is also the case when I reply to certain emails. For example, I just
decided to comment on one of Cringely's articles, and Outlook was invoked,
even though gmail was already open.

-- 
Arthur
Cell: 647.710.1314

Prediction is difficult, especially of the future.
  -- Niels Bohr