Add a user or group to local administrator group

<#
    .Synopsis
        Adds a user or group to local administrator group

    .Description
        This scripts adds the given user or group to local administrators group on given list of servers.

    .Parameter ComputerName
        Computer Name(s) on which you want to add user/group to local administrators

 .Parameter ObjectType
 This parameter takes either of two values, User or Group. This parameter indicates the type of object
 you want to add to local administrators



 .Parameter ObjectName
 Name of the object (user or group) which you want to add to local administrators group. This should be in
 Domain\UserName or Domain\GroupName format

    .Example
        Set-LocalAdminGroupMembers.ps1 -ObjectType User -ObjectName "AD\TestUser1" -ComputerName srvmem1, srvmem2

        Adds AD\TestUser1 user account to local administrators group on srvmem1 and srvmeme2

    .Example
        Set-LocalAdminGroupMembers.ps1 -ObjectType Group -ObjectName "ADDomain\AllUsers" -ComputerName (Get-Content c:\servers.txt)

 Adds AD\TestUser1 Group to local administrators group on servers listed in c:\servers.txt
    .Notes
 Author : Sitaram Pamarthi
 WebSite: http://techibee.com

#>
[CmdletBinding()]
Param(
 [Parameter(Mandatory=$true,Position=1)]
 [ValidateSet("User","Group")]
 [String]
 $ObjectType,

 [Parameter(Mandatory=$true,Position=2)]
 [ValidateScript({($_.split("\").count -eq 2)})]
 [string]$ObjectName,

 [Parameter(Position=3)]
 [String[]]$ComputerName=$env:COMPUTERNAME
)

#Name and location of the output file. Change this line if you want to alter the location
$ResultsFile = "c:\temp\ResultsofLocalGroupAddition.csv"
$ObjDomain = $ObjectName.Split("\")[0]
$ObjName = $ObjectName.Split("\")[1]
$ComputerCount = $ComputerName.Count
$count = 0
Add-Content -Path $ResultsFile -Value "ComputerName,Status,Comments"
foreach($Computer in $ComputerName) {
 $count++
 $Status=$null
 $Comment = $null
 Write-Host ("{0}. Working on {1}" -f $Count, $Computer)
 if(Test-Connection -ComputerName $Computer -Count 1 -Quiet) {
 Write-Verbose "$Computer : Online"
 try {
 $GroupObj = [ADSI]"WinNT://$Computer/Administrators"
 $GroupObj.Add("WinNT://$ObjDomain/$ObjName")
 $Status = "Success"
 $Comment = "Added $ObjectName $ObjectType to Local administrators group"
 Write-Verbose "Successfully added $ObjectName $ObjectType to $Computer"
 } catch {
 $Status = "Failed"
 $Comment = $_.toString().replace("`n","").replace("`r","")
 Write-Verbose "Failed to add $ObjectName $ObjectType to $Computer"
 }

 Add-Content -Path $ResultsFile -Value ("{0},{1},{2}" -f $Computer,$Status,$Comment )

 } else {
 Write-Warning "$Computer : Offline"
 Add-Content -Path $ResultsFile -Value ("{0},{1}" -f $Computer,"Offline")
 }

}