 <p>You can get path of executable of default browser from registry (look at the following answer for example: <a href="http://stackoverflow.com/a/17599201/2870402">http://stackoverflow.com/a/17599201/2870402</a>) and create new process passing the URL as the parameter:</p> <pre><code>string pathToExecutable = ...; string url = @"file:///c:\Projects\HTMLTest\Debug\help\index.htm#Modules\Administration\UserInterface\MainWindow\Processing.htm"; System.Diagnostics.Process.Start(pathToExecutable, url); </code></pre>