You can silently uninstall GeoEvent Server by running the msiexec.exe command.
- Open a command prompt.
- Execute one of the following command to uninstall your version of ArcGIS GeoEvent Server:10.7.1
msiexec /x {3AE4EE62-B5ED-45CB-8917-F761B9335F33} /qb10.7msiexec /x {7430C9C3-7D96-429E-9F47-04938A1DC37E} /qb