Sometimes you need to add users or groups in local Administrators group on a windows server. This function helps to accomplish that on one or more servers. Load a text- or csv-file and pipe it to Add-AdminGroup. All servers not responding will be shown at the end for later follow-up.
function Add-AdminGroup
{
Param (
[parameter(Mandatory = $true,
ValueFromPipeline = $true,
position = 0)]
[Alias('IPAddress', '__Server', 'CN', 'server')]
[string[]]$Computername,
[parameter(ValueFromPipelineByPropertyName)]
[Alias('groupname', 'adgroup')]
[string[]]$group
)
Process
{
if (Test-Connection -quiet -Computername $computername)
{
Write-Output "Adding $group to local administrators on" $Computername
Invoke-Command -ComputerName $Computername -ScriptBlock {
Add-LocalGroupMember -Group Administrators -Member $args[0]
} -ArgumentList $group
}
else
{
write-output "No response from" $Computername
$failed += $computername
}
}
end
{
foreach ($obj in $failed)
{
Write-Output $obj
}
}
}
Jonas Dahlgren's Blog 