Agent Upgrade Fails with Error "Windows upgrade must be performed by an administrator"Issue The error message "Agent upgrade Failed. Check output: Windows upgrade must be performed by an administrator " may be seen when using the Agent Client Collector Self-Upgrade feature.CauseThis error is misleading. It's not talking about the instance user that's clicking the upgrade button at all. It means the agent's Windows service login as user needs to be a local administrator. By default, the user for the service that is automatically created by the installer is not a local administrator. Using an administrator user as the service user isn't really a good idea in the first place, as most things don't need it, and the principle of least privilege applies, so this does tend to limit the whole feature's usefulness. Note: Until ACC-F v3.2.0 (August 2023), it was also possible that this was a false error, if the user is a domain user. See:PRB1627311/KB1212100 Upgrade Agent fails with error "Windows upgrade must be performed by an administrator" if user is a domain user in local administratorResolutionIf you are OK with running the Agent as an Administrator user, then that's the solution. You may already need that for certain ACC-V checks such as SAM usage and fetching logged in users to work correctly anyway. Alternatively, use your own automation to upgrade the agents, in a similar way to how you probably install them.