On a Windows installation, the elements you create from within GeoEvent Processor Manger (e.g. Inputs, Outputs, GeoEvent Services, GeoEvent Definitions, GeoFences, registered Data Stores, etc.) are persisted beneath C:\ProgramData\Esri\GeoEventProcessor. The folders you find here are not removed when you uninstall the product. They are left behind deliberately so that you can leverage what you created when upgrading to a new product release.
If you first stop the Windows service being used to run GeoEvent Processor and then delete the sub-folders beneath C:\ProgramData\Esri\GeoEventProcessor ... leaving the .\certs folder ... you will have removed the elements you previously created.
The C:\ProgramData\Esri\GeoEventProcessor directory structure will be rebuilt when you restart GeoEvent Processors' Windows service.
To more thoroughly reset your product installation you will need to remove the persisted cache and files used by the product during runtime. Beneath your ArcGIS for Server product installation directory (C:\Program Files\ArcGIS\Server is the default for Windows systems), locate the ...\GeoEventProcessor\data folder. If you first stop the Windows service being used to run GeoEvent Processor and then delete the data folder you will reset GeoEvent Processor to how you find it immediately following a new product installation. The ...\GeoEventProcessor\data folder will be rebuilt when you restart GeoEvent Processors' Windows service.
Hope this information helps -
RJ
