There has been numerous reports that the Microsoft Update KB3038314 (Cumulative security update for Internet Explorer: April 14, 2015) caused problems with the Search Provider functionality in IE. Additionally in some configurations, the error Windows Update encountered an unknown error error code 80092004 turned up when users tried to install this cumulative update.
There is no fix for these problems right now, but Microsoft is aware of these issues and reportedly working on a solution at present.
If you haven’t installed this update, it’s better. For now, you can even hide the update. To do so, open Windows Update applet, right-click the update Cumulative Security Update for Internet Explorer (KB3038314) and click Hide update.
For those who have installed this update already would be facing a problem where IE search providers cannot be added. This issue is also reported and known to Microsoft. I’d simply wait for a fix from Microsoft in the coming days, while others might prefer to simply uninstall the KB3038314 to restore the ability to add search providers to Internet Explorer.