Check for previous version of application
<p>I want to show a What's New form in my application. However I need to detect whether it's  a new install, or an upgrade.</p>

<p>I'm using the following code to upgrade the settings:</p>

<pre><code>if (Properties.Settings.Default.settingsUpgrade)
{
    WhatsNew WhatsNew = new WhatsNew();
    WhatsNew.Show();
    WhatsNew.BringToFront();

    Properties.Settings.Default.Upgrade();
    Properties.Settings.Default.settingsUpgrade = false;
    Properties.Settings.Default.Save();                
}
</code></pre>

<p>The <code>Properties.Settings.Default.settingsUpgrade</code> is set to <code>True</code> by default. However this code will bring up the Whats New form always, even with a new installation.</p>

<p>The <code>Properties.Settings.Default.Upgrade();</code> doesn't have an event or something which is fired when the upgrade actually was needed, so I have no idea if there was a previous version (and thus show the Whats New form). How do I know if there was a previous version?</p>
