private/dev/Get-MyDeviceManufacturer.ps1

function Get-MyDeviceManufacturer {
    [CmdletBinding()]
    param ()
    $deviceManufacturer = (Get-CimInstance -ClassName CIM_ComputerSystem -ErrorAction Stop).Manufacturer
    $deviceManufacturer = $deviceManufacturer -as [string]
    if ([string]::IsNullOrWhiteSpace($deviceManufacturer)) {
        $deviceManufacturer = 'OEM'
    } else {
        $deviceManufacturer = $deviceManufacturer.Trim()
    }
    if ($deviceManufacturer -match 'Dell') { $deviceManufacturer = 'Dell' }
    elseif ($deviceManufacturer -match 'Lenovo') { $deviceManufacturer = 'Lenovo' }
    elseif ($deviceManufacturer -match 'Hewlett|Packard|\bHP\b') { $deviceManufacturer = 'HP' }
    elseif ($deviceManufacturer -match 'Microsoft') { $deviceManufacturer = 'Microsoft' }
    elseif ($deviceManufacturer -match 'Panasonic') { $deviceManufacturer = 'Panasonic' }
    elseif ($deviceManufacturer -match 'OEM|to be filled') { $deviceManufacturer = 'OEM' }
    return $deviceManufacturer
}