It also has Windows 10 installed. Deep integration of the browser into the OS is one reason Windows is so popular. Since IE is there, and every application developer can rely on it to be there, that's just what they do. Sometimes this is less than optimal, though
Here's the latest case in-point: Google Drive. I use Google Drive as part of my work at NVIDIA. This means that it has been approved by corporate I.T. It also means we authenticate with SSO.
But when I went to sign in to Google Drive, nothing happened. I clicked and clicked the Next button, but the app never moved.
This helped explain things! Apparently IE 9 didn't allow for redirects, or didn't like SSO in some fashion. So naturally I started googledrivesync.exe on the command line with the mentioned flag.
C:\Program Files (x86)\Google\Drive>googledrivesync.exe --ie_version=11
But here's the really goofy part...
When I gave my SSO login, it just hung there - again!
So I hit the <Backspace> key, which took me back to the Google login page above. I entered my email and password, clicked Next, and this time it took me to the "First time login experience" wizard, explaining to me what Google Drive was. Only when I completed the wizard was I then considered logged in!
And that did the trick! Google Drive let me login with the corporate SSO page.