You can silently uninstall 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:
10.5.1
msiexec /x {F11BBE3B-B78F-4E5D-AE45-E3B29063335F} /qb
10.5
msiexec /x {D71379AF-A72B-4B10-A7BA-64BC6AF6841B} /qb