The Search app in Windows 8.1 is located inside the file %windir%\System32\Windows.UI.Search.dll and its resources are stored in the %windir%\SystemResources\Windows.UI.Search folder. Windows 8.1 featured a standalone Search app which was capable of running even when UAC is disabled. In Windows 10, the Search app became Cortana and got its own tile and AppID, Microsoft.Cortana_8wekyb3d8bbwe.
