Deploy Agent via GPO excluding existing installations.
In our organization, we deployed the Kace Agent in multiple ways. We used the agent provisioning, then we started using a login script that ran with admin credentials. Now I would like to strictly use a GPO to push out the agent. However, I'd prefer not to send out the client again if a machine already has it. My understanding is that a "assign software" GPO will not run if the registry key already exists for that GPO. (HKLM\Software\Microsoft\Windows\CurrentVersion\Group Policy\AppMgmt) under that, there will be a key with a unique ID specific to the GPO.
Anyway what I'm trying to accomplish is, creating an offline script that runs that adds the required key to the registry and apply the script to all computers. That way obviously if the client has the agent installed it will add that registry key. Then when I deploy via a GPO any missing will get it.
Has anyone done anything like this? Are there limitations, or anything I'm missing?