Remove Pop-up Error: "Only secure content is displayed" on IE9

1. In Internet Explorer 9, go to Tools menu > Internet options.
2. Under the Security tab, click on the Custom level… button (be sure that Internet is selected under "Select a zone to view or change security settings").
3. A Security Settings window will appear with numerous options, scroll down a little past half way down, you will see an option labeled Display mixed content, there you can choose Enable (which will always display non-secured items without asking) or Disable (which will not display non-secure items).
4. Click OK, and a dialog asking if you are sure you want to change the settings for this zone, be sure to click Yes.
5. Now click Apply and you are done.
Note: Based on the Microsoft web site, the reason for the secure content message in Internet Explorer 9 is to help protect you from security threats. The warning is letting you know that you are on a secure (HTTPS) page that is attempting to load non-secure (HTTP) content.