https://en.wikipedia.org/wiki/WinHelp
https://en.wikipedia.org/wiki/Microsoft_Compiled_HTML_Help
https://en.wikipedia.org/wiki/Microsoft_Help_2
https://en.wikipedia.org/wiki/Microsoft_Assistance_Markup_Language
https://en.wikipedia.org/wiki/Microsoft_Help_ViewerFinally their updated product (like Explorer) just open website or even Bing search result.