Don't know if this has been posted before but the first time I've run into it. I have been deploying the ZEN 11 Agents through the control panel without issue except for one area. It keeps coming back failed with no explanation, but had two machines where it tried to install. One worked the other came back as initializing. All the machines have ZEN 7 agents. So I went out to the area and started manually installing on the other machines by removing ZEN 7 and then deploying the agent from the web site. The machine though that was still trying to initialize (after a week) didn't show ZEN 7 or 11. I rebooted the machine.

Here's where the fun began, after it restarted, I tried to manually remove ZEN 7 through control panel and nothing. The control panel didn't show CASA being installed or the ZEN 11 agent. So I manually ripped out ZEN 7 because trying to reinstall 7 didn't work either. Spent most of the morning cleaning out the registry and such. Once I figured it was all removed I tried installing ZEN 11.1. At first it gave me a status, (after an hour) I stopped the process and tried the ZEN 11 removal/cleaning tool. That didn't work but I did get a new status. Try to clean it out some more. Now every time I try to install, it says the PreAgent fails and to check the Event Viewer.

One of the issues I found was when I deployed the Agent the desktop was only on SP 2. So after cleaning everything out, I installed all SP's and have it current, but still have the same problems.

I've attached the application.evt log where there is a large number of Information entries but one Error saying Previous agent uninstallation failure msiexec.error 1605

Can anyone guide me on even though I believe the agent is removed, why the new agent won't install?