Problems creating vms dashboard and alerts with WMI_Exporter as client

Hello guys, I need to create a very simple dashboard for Windows machines. These have a WMI_Exporter installed as a client. Prometheus takes it perfectly.
Grafana is also perfect. He sees it without problems.
The drama is that I want to create a simple dashboard with an alert that tells me when the machine is off or on.
I created some, but the machine disappears from the dashboard and does not issue an alert error message.
Do you have any guide?