It can be run against a multiple remote machines in bulk and export the collected data into CSV file:

This utility can be useful if you lost the product key of your Windows, and you want to reinstall it on your computer.
Note that if the Windows product key is not stored in the Registry (like in volume licenses) it will be displayed partially.

Code Snippet:

Try 
            { 
                #License Info 
                $LicenseInfo = Get-WmiObject SoftwareLicensingProduct -ComputerName $target -Credential $cred -ErrorAction Stop | ` 
                Where-Object { $_.PartialProductKey -and $_.ApplicationID -eq "55c92734-d682-4d71-983e-d6ec3f16059f" } | Select-Object PartialProductKey, Description, ProductKeyChannel, @{ N = "LicenseStatus"; E = { $lstat["$($_.LicenseStatus)"] } } 
                $win32os = Get-WmiObject Win32_OperatingSystem -computer $target -Credential $cred -ErrorAction Stop 
                $WindowsEdition = $win32os.Caption 
                $ServicePack = $win32os.CSDVersion 
                $OSArchitecture = $win32os.OSArchitecture 
                $BuildNumber = $win32os.BuildNumber 
                $RegisteredTo = $win32os.RegisteredUser 
                $ProductID = $win32os.SerialNumber 
                $PartialProductKey = $LicenseInfo.PartialProductKey 
                If ($LicenseInfo.ProductKeyChannel) 
                { 
                    $LicenseType = $LicenseInfo.ProductKeyChannel 
                } 
                Else 
                { 
                    $LicenseType = $LicenseInfo.Description.Split(",")[1] -replace " channel", "" -replace "_", ":" -replace " ", "" 
                } 
                $LicenseStatus = $LicenseInfo.LicenseStatus 
            }