Internet Explorer - Prevent programs from suggesting changes to your default search provider
Some programs (browser extension, toolbars,...) may suggest that you change your default search engine, which can be very annoying!
Internet Explorer includes a protection mechanism to prevent this from happening, so here's how to enable it:
Click on Tools > Safety > Manage Add-ons.
Click on the Search providers tab.
Tick the "Prevent programs from suggesting changes to my default search provider" checkbox.