Get Windows activation status, taken from slmgr.vbs and ignoring KMS and AD and other product licensing, and older versions.

gistfile1.txt

Get-CimInstance -ClassName SoftwareLicensingProduct |
    Where-Object {$_.ApplicationId -eq "55c92734-d682-4d71-983e-d6ec3f16059f" -and $_.PartialProductKey } |
    Select-Object Name, 
            @{Name="LicenseStatus"; Expression = { 
                switch ($_.LicenseStatus) { 0       { "Unactivated"}
                                            1       { "Activated"  } 
                                            default { "unknown"    }
                                            } } }