> For the complete documentation index, see [llms.txt](https://docs.foundryosd.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.foundryosd.com/foundry-osd/customization/optional-features.md). # Optional features **Optional features** turns Windows optional features on or off in the deployed Windows, for example .NET Framework 3.5, Hyper-V or Windows Sandbox. A feature you do not set stays as the Windows image has it.
Foundry OSD Optional features page with the search box, the Enable all, Disable all and Reset all buttons, and the feature categories, each with its state menu

Expand a category to set each feature. The line under a feature's name gives its DISM feature name, its availability and any warning.

## Configure features 1. Open **Customization > Optional features** and turn the switch at the top right to **Enabled**. 2. Find the feature. Expand a category, or type in the search box: it matches the display name or the DISM feature name, such as `NetFx3`. 3. Read the line under the feature name. It gives the availability and warnings such as "Requires compatible virtualization hardware and firmware settings." 4. Open the menu on the feature's row and choose a state. 5. Create or update the deployment media. | State | Effect on the deployed Windows | | ----------------------- | ----------------------------------- | | **Unchanged** (default) | Foundry does not touch the feature. | | **Enable** | Foundry turns the feature on. | | **Disable** | Foundry turns the feature off. | A state applies to the feature and to all its sub-features. Choosing **Enable** on a sub-feature whose parent is set to **Disable** resets the parent to **Unchanged**. The page lists 131 features in 19 categories. The card at the top counts your choices, for example "3 configured (2 enable, 1 disable)". To change several features at once: * **Enable all**, **Disable all** and **Reset all** act on every feature listed and on their sub-features. With a search active, they act on the search results only. **Reset all** returns the features to **Unchanged**. * The menu on a category row offers **Enable visible items**, **Disable visible items** and **Reset visible items** for that category. * When a button changes 10 features or more, Foundry OSD asks "This will update \ affected features, including descendants. Do you want to continue?"
Availability labels The label compares the feature with the versions and editions ticked on [OS selection](/foundry-osd/customization/operating-system.md), or with all supported ones when that page is off. | Label | Meaning | | ------------------------------------------------------------------- | ------------------------------------------------------------------------ | | **Available for all selected targets** | Every ticked version and edition has the feature. | | **Available for some selected targets** | Only some of them have it. | | **Not available for the selected targets** | None of them has it. | | **Availability will be verified against the applied Windows image** | Foundry OSD cannot tell in advance. Foundry Deploy checks on the device. | The labels describe catalog images. Foundry does not evaluate them for a custom Windows image.
## What happens on the device Foundry Deploy applies the changes in Windows PE, in the **Configure Windows features** step, after Windows is applied to the disk. It works offline. The page says so: "Enable operations use only the installed image or matching setup-media sources; no Internet fallback is used." | Situation in the applied Windows | Result | | ---------------------------------------------------------------------------- | ------------------------------------------------------------------------------ | | The feature is already in the state you asked for | Nothing to do. Counted as "already satisfied". | | **Enable**, and the image does not know the feature | The feature is skipped and the deployment continues. Counted as "unavailable". | | **Disable**, and the image does not know the feature | Counted as "already satisfied". | | **Enable**, and the image knows the feature but no longer contains its files | The deployment stops, except for the .NET Framework 3.5 features below. | The step ends with "Windows optional features configured (\ changed, \ already satisfied, \ unavailable)." An "unavailable" count above zero means a feature you asked for was not turned on, although the deployment succeeded. The Foundry Deploy log then contains "Skipped \ unavailable Windows optional feature enable action(s)." When no feature needed a change, the **Steps** list marks the step as skipped, and pointing at it shows the "Windows optional features configured" line with 0 changed. ## Limits * **No download.** A feature whose files are not in the Windows image cannot be turned on. Add it after deployment, with Internet access. * **.NET Framework 3.5 needs a catalog image.** Five features carry the line "Enabling this feature requires a matching setup-media sources\sxs payload.": **.NET Framework 3.5 (includes .NET 2.0 and 3.0)**, its two **Windows Communication Foundation** activation features, **.NET Extensibility 3.5** and **ASP.NET 3.5**. Foundry Deploy takes their files from the Windows image it downloads from the Foundry catalog. * **Recall.** The **Recall** feature adds or removes the Windows component. **Disable Windows Recall by policy** on [AI components](/foundry-osd/customization/ai-components.md) is a separate setting. * **Windows Subsystem for Linux.** The feature installs the Windows component only, not a Linux distribution. {% hint style="warning" %} **.NET Framework 3.5 and custom Windows images** A [custom Windows image](/foundry-osd/customization/custom-windows-images.md) does not carry the files these five features need. If one of them is set to **Enable** and is not already on in the image, the deployment stops at **Configure Windows features**, after the disk has been erased, with "Setup-media image '\' must contain exactly one image named 'Windows Setup Media'." Turn the feature on inside the image before you capture it, or leave it **Unchanged**. {% endhint %} ## Related * [OS selection](/foundry-osd/customization/operating-system.md) * [Custom Windows images](/foundry-osd/customization/custom-windows-images.md) * [Review and deploy](/foundry-deploy/review-and-deploy.md) * [Failed step: Configure Windows features](/troubleshooting/deployment/after-disk-erase.md#optional-features), in Windows deployment troubleshooting --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.foundryosd.com/foundry-osd/customization/optional-features.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.