Setting the Pulseway Computer name to the Locally logged in username

So, I have this:   Set-ItemProperty -Path "HKLM:\Software\MMSOFT Design\PC Monitor\" -Name ComputerName -Value "$env:UserName" Which works great from the local machine via PowerShell, However, when I try to run this as a script/task, the name just shows up as "HOSTNAME$" Any ideas why?
Ok, that makes more sense. In that case I needed to take advantage of WMI. My final code is this, which works great! $temp = Get-WmiObject -Class Win32_ComputerSystem | Select-Object -ExpandProperty username $UserName = $temp -replace ".*\\", "" Set-ItemProperty -Path "HKLM:\Software\MMSOFT Design\PC Monitor\" -Name ComputerName -Value "$UserName" Thanks for the help!