terraform build ec2 windows

I am trying to use terraform to build a simple aws ec2 instance running windows 2016 server. I successfully build the ec2 windows instance but I can't connect into the server. How do I set username and password after the server is built so I can RDP into it?

resource "aws_instance" "win2k" {
...
...  
...
// Test connectivity to newly built ec2
connection {
  type        = "winrm"
  user        = "Administrator"
  password    = "${var.admin_password}"
}



# Set local admin user/pass
user_data = <<EOF

<script>
winrm quickconfig -q & winrm set winrm/config @{MaxTimeoutms="1800000"} & winrm   set winrm/config/service @{AllowUnencrypted="true"} & winrm set winrm/config  /service/auth @{Basic="true"}
</script>

<powershell>
netsh advfirewall firewall add rule name="WinRM in" protocol=TCP dir=in   profile=any localport=5985 remoteip=any localip=any action=allow
# Set Administrator password
$admin = [adsi]("WinNT://./administrator, user")
$admin.psbase.invoke("SetPassword", "${var.admin_password}")
</powershell>
EOF