1. Change the installer executable icon or the icon showed in Start Menu folder
Using SetupIconFile
[Setup]
SetupIconFile=MyFolder\INF.ico
2. Change the icon displayed in Add/Remove Programs Control Panel
Using UninstallDisplayIcon
[Setup]
UninstallDisplayIcon= {app}\INF.ico
References:
http://*.com/questions/5170456/is-it-possible-to-change-the-uninstall-icon-in-inno-setup