I am trying to uninstall third-party antivirus software on an endpoint (client workstation)



You might want to try this:

If you manage your network remotely:

Remove third-party antivirus software from client computers using ESET Security Management Center (7.x)


If you do not use a remote management platform, you can use ESET AV Remover tool:

ESET AV Remover—List of removable applications and instructions to run the tool

Uninstallers (removal tools) for common Windows antivirus software

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