Process.Start to open an URL, getting an Exception?

I'm trying to open an URL following a simple method written all over google and even MSDN. But for unknown reasons I get an Exception as follows:

Win32Exception was unhandled

Message: Application not found

Here's my code:

private void linkLabel_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
    ProcessStartInfo sInfo = new ProcessStartInfo("http://github.com/tbergeron/todoTxt");
    Process.Start(sInfo);
}

Any idea why it is failing?

Thanks a lot!