InTrust agent automatically unregistered by the InTrust server after 11 days or more when there is no site, rule and job assigned
There is a organization parameter that controls un-installation of an agent that is not use by an InTrust server (not participating in any InTrust site, rule, gathering job and etc) is "agent_cleanup_after". By default, it is set to 864000 seconds (10 days). There is also a pair to this parameter, called "agent_cleanup_last_chance_period". It is supposed to control the total online time of the InTrust Server service during which it waits after the "agent_cleanup_after" period expiration before it actually tries to remove the agent registration. By default this parameter is set to 24 hours (86400) and normally (unless you stop the adcrpcs.exe service frequently and for a long time) it just means that the default agent cleanup period is 10+1=11 days.
1. Right click on Quest InTrust Manager (local) and click Properties
2. Select Parameters tab
3. Increase the value of "agent_cleanup_after" parameter to something big (e.g 86400000).