The service account used by the collector needs the ability to restart the collector services. Without this right, the collector and its associated watchdog will not be able to restart each other. If you find your collectors periodically going down after 8 hours or so, group policy permissions could be preventing them from restarting themselves or one another.
Ensure the account you specify for the LogicMonitor Collector and LogicMonitor Collector Watchdog services has the Read permission, and the Stop, Start, and Pause permissions to these services.
For more information about how to grant these permission, consult your Microsoft documentation. An article with step-by-step instructions can also be found at:https://social.technet.microsoft.com/wiki/contents/articles/5752.how-to-grant-users-rights-to-manage-services-start-stop-etc.aspx.