> For the complete documentation index, see [llms.txt](https://www.osdeploy.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.osdeploy.com/command-reference/osdeploy/update-osdeploybootiso.md).

# Update-OSDeployBootISO

Rebuilds the bootable ISO files for a selected OSDeployCore BootImage build.

| Property | Value                                                                                   |
| -------- | --------------------------------------------------------------------------------------- |
| Module   | OSDeploy                                                                                |
| Platform | Windows 11 25H2 build 26200 or later (amd64 / arm64)                                    |
| Requires | Valid license, Run as Administrator, Windows ADK installed, a completed BootImage build |

## Description

Regenerates the ISO files (`bootmedia.iso` and optionally `bootmedia_ca2023.iso`) for a selected completed BootImage from `%ProgramData%\OSDeployCore\boot`. The existing `bootmedia` directory content is used as-is — no DISM mount or WIM modification is performed.

The function:

* Prompts for selection of a completed BootImage build
* Verifies the Windows ADK is installed
* Uses the installed ADK's `oscdimg.exe` to rebuild the ISO(s)
* Places the resulting ISOs in the BootImage's root directory

Use this function when you need to regenerate an ISO from existing bootmedia files without rebuilding the entire WinPE image. Use `Build-OSDeployBoot` to perform a full rebuild.

## Syntax

```powershell
Update-OSDeployBootISO [-WhatIf] [-Confirm]
```

## Parameters

The BootImage selection is made with an interactive `Out-GridView` picker.

| Parameter  | Type     | Required | Description                                   |
| ---------- | -------- | -------- | --------------------------------------------- |
| `-WhatIf`  | `Switch` | No       | Preview ISO creation after selecting a build. |
| `-Confirm` | `Switch` | No       | Confirm each ISO creation operation.          |

## Examples

```powershell
# Prompt for a BootImage build selection and rebuild its ISO files
Update-OSDeployBootISO
```


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