Opening the Internet Browser Programmatically

public static string GetDefaultBrowser()
{
    string browser = string.Empty;
    Microsoft.Win32.RegistryKey key = null;
    try
    {
	object obj = null;
	key = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(@"HTTP\shell\open\command", false);
	if (key != null)
	{
	    obj = key.GetValue(null);
	    if (obj != null)
	    {
		browser = Convert.ToString(obj);
	    }
	}

	if(string.IsNullOrEmpty(browser))
	{
	    key = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Classes\Applications\iexplore.exe\shell\open\command", false);

	    obj = key.GetValue(null);
	    if (obj != null)
	    {
		browser = Convert.ToString(obj);
	    }
	}

	if (!string.IsNullOrEmpty(browser))
	{
	    //trim off quotes
	    browser = key.GetValue(null).ToString().ToLower().Replace("\"", "");
	    if (!browser.EndsWith("exe"))
	    {
		//get rid of everything after the ".exe"
		browser = browser.Substring(0, browser.LastIndexOf(".exe") + 4);
	    }

	    //Enable quotes again
	    browser = '"' + browser + '"';

	    return browser;
	}
    }
    catch
    {
	//noop
    }
    finally
    {
	if (key != null) key.Close();
    }

    return string.Empty;
}