If you don't know (or haven't encountered it yet) there is a bug in VS that causes the settings of the default browser to not save.
For example: I am using Firefox as my default Windows browser but prefer debugging using IE (mainly because if IE dies my browser is still alive). And I have to change the browser much too often.
There isn't a fix for this but there is a workaround:
From VS -> Tools -> Extension Manager
-> Online Gallery -> Search:
WoVS Default Browser Switcher
Download and install the extension and when prompt restart VS.
Now in VS: View -> Toolbar -> enable: Default Browser Switcher
And you will get:
(image from WoVS Default Browser Switcher extension page)
And you will see what default browser is turned on.
I prefer putting it just below the debug toolbar so that it will be in front of my eyes but you can place it where ever you may like…
There is also a context menu for viewing web pages but it is not as useful as the toolbar.
You can read more about it here.