You can silently uninstall ArcGIS GeoEvent Server by running the msiexec.exe command.
- Open a command prompt.
- Execute one of the following commands to uninstall your version of ArcGIS GeoEvent Server:10.9.1
msiexec /x {F5C3D729-0B74-419D-9154-D05C63606A94} /qb10.9msiexec /x {B73748C3-DD75-4376-B4DA-D52C59121A10} /qb