you have instaled the agent by using bat file, the date file consists of following
msiexec /i AgentInstall64.msi /q INSTALLDIR="C:\Program Files\Manufacturer\Endpoint Agent\" ENDPOINTSERVER="hostname" KEY="" SERVICENAME="EDPA" WATCHDOGNAME="WDP" ARPSYSTEMCOMPONENT="1"
IF you change Arpsystemcomponent = 0 then it will be shown in add remove programm.
Now even if it is not showing in add-remove programm, you can use the bat file uninstall_agent.bat to uninstall this agent.