[Windows] elastic-agent installed via MSI installer does not completely uninstall

[michel-laterman]

Running elastic-agent uninstall on a Windows system after installing the agent with an MSI package does not fully remove all references from the system.

• Version:8.18+
• Operating System: Windows
• Discuss Forum URL: N/A
• Steps to Reproduce:
  1. Install elastic-agent using an MSI install on Windows, see official docs.
     Note how the installer creates a C:\Program Files\Elastic\Beats directory
  2. run elastic-agent uninstall
  3. The Beats directory still exists on the system.
     Additionally, Elastic Agent will still be listed in the system's Installed Programs list.

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[ebeahan]

https://github.com/elastic/elastic-stack-installers?tab=readme-ov-file#uninstall mentions the .msi acts as a wrapper to elastic-agent uninstall, but it's possible just calling elastic-agent uninstall isn't handling all the necessary steps to properly uninstall the package.

I wasn't able to (quickly) find any guidance of how to uninstall the MSI in our docs or in https://github.com/elastic/elastic-stack-installers. What's the experience if the original MSI or something like msiexec is used to uninstall?

[gord-lyr]

Using "msiexec /x elastic-agent-x.x.x.msi" or "msiexec /x {elastic-guid}" has the same results as running "elastic-agent uninstall" --notably the Beats directory is still present and the application still appears in Add/Remove programs.

NOTE: Testing performed with 8.18.4 installer

[cmacknz]

Thanks, there probably shouldn't even be a Beats directory (likely left over from using the Beat MSI as the starting point for Agent), and the Add/Remove programs sounds like it isn't not cleaning up a registry key.

Agent doesn't touch the registry itself so this is purely an MSI problem, even though agent probably should update the registry itself. elastic/elastic-agent#2510