Internet Explorer's Compatibility Mode is a feature intended to allow old websites to be view-able with newer versions of Internet Explorer. When this feature is used with newer websites, unintended consequences may occur which render the new site unusable.
If you receive the error, "Please disable Compatibility Mode to continue using Online Banking." you can disable this feature by taking the following steps:
1. Within Internet Explorer click "Tools" then "Compatibility View Settings" from the top menu.
2. In the resulting dialogue box, review the entries listed under "Websites you've added to Compatibility View".
3. If you see an entry for "fnb-onlinebankingcenter.com" in the list, please left-click on the URL to highlight it and then click "Remove".
4. Finally, click "Close" and then log in to Online Banking as needed.