I\'m using this to get the path and executable of default web browser:
public static string DefaultWebBrowser
{
get
{
You can replace all that code with
System.Diagnostics.Process.Start(pathToHtmlFile);
This will automatically start your default browser, or rather look up the default handler for .htm or .html files and use that.
Now with Firefox set as default this can sometimes cause weird exceptions (I think if Firefox is starting for first time), so you might want to do a try/catch on it to handle that.