As I recall:
Microsoft Windows used to have good online help, circa 1991-1994 (Windows 3.1).
It was based on the Rich Text Format (RTF).
Then Microsoft added a web browser, and called it Internet Explorer.
Internet Explorer really wasn't very good for exploring the internet, apparently because its development had been rushed and it didn't display some things like other browsers would.
Then Microsoft argued in court that its web browser was an integral part of Windows, which Windows could not work without.
Then the judge removed the web browser from his own Windows-based computer and experienced no problems.
Then Microsoft changed its online help to HTML and made us use its web browser to access it.