This post describes best practices for setting default search provider on Internet Explore 8. If multiple search providers try to reset registry key every time it changes, it causes a confusing and frustrating user experience. Dialog box will re-appear every time key’s modified directly. IE8 includes a Search Provider Default configuration experience designed for this scenario. When your software uses IOpenServiceManager API and SetDefault API, users will see clearer communication about what’s happening. This transparency’s an important part of user being in control. If binary that’s calling SetDefault API is signed with a valid code signing certificate, program name and publisher will be displayed in Search Provider Default dialog box. In summary, if your software monitors DefaultScope registry key directly, please update your code to use recommended APIs. This’ll allow user to see search provider default dialog only once and lets them be in full control of their default, in support of Guidelines for add-on development. If you’re new to OpenSearch Extensibility and would like to learn how to offer your services or how to get started, check Search Provider Extensibility in Internet Explorer article.