{
  "if": {
    "allOf": [
        {
          "field": "type",
          "equals": "Microsoft.Compute/virtualMachines"
        },
        {
          "field": "Microsoft.Compute/imageOffer",
          "equals": "WindowsServer"
        }
    ]
  },
  "then": {
      "effect": "[parameters('effect')]",
      "details": {
        "type": "Microsoft.Compute/virtualMachines/extensions",
        "existenceCondition": {
          "allOf": [
            {
              "field": "Microsoft.Compute/virtualMachines/extensions/type",
              "equals": "NetworkWatcherAgentWindows"
            }
          ]
        },
        "roleDefinitionIds": [
          "/providers/Microsoft.Authorization/roleDefinitions/b24988ac-6180-42a0-ab88-20f7382dd24c"
        ],
        "deployment": {
          "properties": {
            "mode": "Incremental",
            "template": {
              "$schema": "http://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
              "contentVersion": "1.0.0.0",
              "parameters": {
                  "vmName": {
                      "type": "String"
                  },
                  "location": {
                      "type": "String"
                  }
              },
              "resources": [
                  {
                      "type": "Microsoft.Compute/virtualMachines/extensions",
                      "apiVersion": "2015-06-15",
                      "name": "[concat(parameters('vmName'),'/AzureNetworkWatcherExtension')]",
                      "location": "[parameters('location')]",
                      "properties": {
                          "publisher": "Microsoft.Azure.NetworkWatcher",
                          "type": "NetworkWatcherAgentWindows",
                          "typeHandlerVersion": "1.4",
                          "autoUpgradeMinorVersion": true,
                          "settings": {}
                      }
                  }
              ],
              "outputs": {
                "policy": {
                  "type": "string",
                  "value": "[concat('Enabled NetworkWatcher for Windows VM', ': ', parameters('vmName'))]"
                }
              }
            },
            "parameters": {
              "vmName": {
                "value": "[field('name')]"
              },
              "location": {
                "value": "[field('location')]"
              }
            }
          }

        }
      }
  }
}