Remote Sensor Elevated Status

I need to be alerted if a website is up, and not if it's down. It's a backup site that shouldn't be running if the primary site is functioning. So I've setup a sensor with a PowerShell script on a remote probe which checks if that IIS site is up. However, when I run the sensor the log on the remote server says, "Process should have elevated status to access IIS configuration data."

UAC is enabled on the server. Any ideas how I can run a powershell script with elevated privileges? Or is there a better way to accomplish this?

Here's the script (minus try/catch):

$script:Exception = $null;
Import-Module WebAdministration
$site = Get-Website -Name "*BackupSite*"
if ($site.state = "Stopped")
{
	$x=[string]"0:OK"
	write-host $x
	exit 0
}
else
{
	$x=[string]"1:WARNING"
	write-host $x
        exit 1
}

powershell prtg sensor