Best is a fresh install - re-doing the config also is not a bad idea! In order to clear all the collector information from the machine, un-install it and once it is cleared please verify if you have any files in the following folder and remove them as well: C:\ProgramData\CheckPoint\identity collector. In addition, check the registry folder and see if you have anything under:
"HKEY_LOCAL_MACHINE -> SOFTWARE -> Wow6432Node -> CheckPoint -> IA" and remove all related to identity collector.
To avoid creating a new configuration, thereby giving a chance for introducing new errors, in very large deployments only uninstall / reinstall is performed.
CCSP - CCSE / CCTE / CTPS / CCME / CCSM Elite / SMB Specialist