---
title: "system.nav.openWindowInstance"
description: "Operates exactly like system.nav.openWindow, except that if the named window is already open, then an additional instance of the window will be opened."
---

# system.nav.openWindowInstance

> Operates exactly like system.nav.openWindow, except that if the named window is already open, then an additional instance of the window will be opened.

This function is used in **Python Scripting**.

## Description
Operates exactly like system.nav.openWindow, except that if the named window is already open, then an additional instance of the window will be opened. There is no limit to the number of additional instances of a window that you can open.

## Client Permission Restrictions
This scripting function has no [Client Permission](projects\project-properties\project-properties.md#client---permissions) restrictions.

## Syntax
`system.nav.openWindowInstance(path [, params])`

### Parameters

|Type|Parameter|Description|
|--|--|--|
|String| `path` |The path to the window to open.|
|PyDictionary| `params` | A dictionary of parameters to pass into the window. The keys in the dictionary must match dynamic property names on the target window's root container. The values for each key will be used to set those properties. [optional]|
### Returns
**PyObject** - A reference to the opened window.
### Scope
Client

## Code Examples
```python title="Code Snippet"
# This example would open three copies of a single HOA popup screen.
  
system.nav.openWindowInstance("HOA", {machineNum:3})
system.nav.openWindowInstance("HOA", {machineNum:4})
system.nav.openWindowInstance("HOA", {machineNum:5})
```