How to Force IE 8 to Compatibility Mode
Internet Explorer 8 contains a compatibility mode that renders websites as they would display on Internet Explorer 7. Internet Explorer 8 behaves differently from previous versions of Internet Explorer, so some Web pages won't work properly unless compatibility mode is enabled. Users can force Internet Explorer 8 to load one or more websites in compatibility mode, or Web developers can add a tag to their page's source code that forces Internet Explorer 8 to load their Web page in compatibility mode.
Click the "Tools" menu at the top right corner of the Internet Explorer 8 window, and select "Compatibility View Settings" in the menu.
Force Internet Explorer to always load a website in compatibility mode by typing the website's domain name in the form "example.com" into the text box, and click "Add." You can also click the "Display All Websites in Compatibility View" check box at the bottom of the window to force Internet Explorer to load all websites in compatibility mode.
Click the "Close" button.
Open your Web page's HTML source code in a text editor.
Add the following tag onto a new line immediately below the "" line in your page's HTML source code:
Save the Web page file on your Web server.