I am looking for a way to restart three services on multiple servers simultaneously. I know how to restart services against a list of servers by using a loop but as I have many
You could try to work with jobs. Jobs are run in the background and you have to retrieve them with Get-Job to see their status. Please read the information to Powershell jobs on these two sites:
http://msdn.microsoft.com/en-us/library/dd878288%28v=vs.85%29.aspx
http://technet.microsoft.com/de-DE/library/hh847783.aspx
Your code would look something like this:
$servernames | ForEach-Object {Start-Job -Name "Job-$_" -Scriptblock {"Enter your code here -Computername $_"}}
This will create a background job for each servername. As already mentioned you can see the status using the cmdlet Get-Job. To get the result use the cmdlet Receive-Job.