####
# Run this script in the user data portion of windows images you want to join to your domain.
# User needs rights to join computers to the domain.
####

<powershell>
$domain = "mydomain.local"
$password = "Password1" | ConvertTo-SecureString -asPlainText -Force
$username = "mydomain\username"
$credential = New-Object System.Management.Automation.PSCredential($username,$password)
Add-Computer -DomainName $domain -Credential $credential -Restart
</powershell>