10_3.ps1

function Set-TMServiceLogon {
    Param(
        [string]$ServiceName,
        [string[]]$ComputerName,
        [string]$NewPassword,
        [string]$NewUser,
        [string]$ErrorLogFilePath
    )
    ForEach ($computer in $ComputerName) {
        $option = New-CimSessionOption -Protocol Wsman
        $session = New-CimSession -SessionOption $option `
                                  -ComputerName $Computer
        If ($PSBoundParameters.ContainsKey('NewUser')) {        #A
            $args = @{'StartName'=$NewUser;
                      'StartPassword'=$NewPassword}
        } Else {
            $args = @{'StartPassword'=$NewPassword}
        }
        Invoke-CimMethod -ComputerName $computer `
                         -MethodName Change `
                         -Query "SELECT * FROM Win32_Service WHERE Name = '$ServiceName'" ` #B
                         -Arguments $args |
        Select-Object -Property @{n='ComputerName';e={$computer}},     #C
                                @{n='Result';e={$_.ReturnValue}}
        $session | Remove-CimSession
    } #foreach
} #function
#A Uses PSBoundParameters
#B CIM query
#C Method result piped to Select-Object