Use PowerShell to start an Azure VM

start_vm.ps1

# --- begin prerequisite ---
# interactive login to Azure Resource Manager with your Azure Account
Login-AzureRmAccount 
# print the list of subscriptions you have access to
Get-AzureRmSubscription
# save your credential to a JSON file for auto-login later on
Save-AzureRmContext  -Path "C:\private\azure-credential.json"
# --- end prerequisite ---

# --- begin script ---
Import-AzureRmContext  -Path "C:\private\azure-credential.json"
Select-AzureRmSubscription -SubscriptionName "MySubscription"
$vm = Get-AzureRmVM -ResourceGroupName "MyResourceGroup" -Name "MyVM"
$vm | Start-AzureRmVM
# --- end script ---