Media creation in Foundry

Foundry is the workstation-side app that creates the deployment media.

Standard settings

The standard section focuses on the main choices required to produce usable media:

• ISO output path
• USB target disk
• Target architecture
• WinPE language
• Included WinPE driver vendors

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Add a capture of the standard media creation pane, with ISO path, USB target, architecture, language, and driver vendor selection visible.

Advanced options

The advanced section exposes the media-level tuning that affects boot behavior and staging:

• CA2023 signature mode
• USB partition style
• USB format mode
• Custom driver directory

These options are part of media authoring, not the live WinPE deployment session.

Do not change advanced media options casually

Only change signature mode, partition style, format mode, or custom driver paths when you have a concrete compatibility requirement.

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Add a capture of the advanced media options pane with the CA2023, partition, format, and custom driver controls visible.

ISO vs USB at a glance

Aspect	ISO	USB
Final output	Single .iso file	Direct provisioning of the selected USB disk
Destructive behavior	No	Yes, the target USB disk is erased and repartitioned
Media layout	Prepared WinPE workspace turned into one ISO artifact	FAT32 BOOT partition plus NTFS Foundry Cache partition
Runtime behavior after boot	Uses the ISO-backed runtime path in WinPE	Bootstrap prefers the persistent USB cache runtime
Cache directories	No dedicated USB-style cache partition	Initializes Runtime, OperatingSystem, and DriverPack directories
Best fit	Reusable artifact, VM testing, remote distribution	Field media, repeated deployments, persistent cache-backed workflows

What both modes have in common

Before Foundry creates either output type, it prepares the same WinPE workspace:

• resolves ADK tooling
• builds the WinPE workspace
• injects drivers
• applies WinPE language components
• provisions Foundry.Connect
• provisions Foundry.Deploy
• stages configuration, network assets, and Autopilot profiles

That shared preparation step is why ISO and USB can carry the same deployment logic even though they finish differently.

How ISO creation works

ISO mode is the simpler packaging path:

1. Foundry prepares the WinPE workspace.
2. Foundry runs MakeWinPEMedia /ISO against that prepared workspace.
3. Foundry writes the final .iso artifact to the requested destination.

For the operator, that means ISO is best when you want a reusable file artifact instead of immediate removable media provisioning.

Deep dive: ISO path handling

If the workspace path or requested ISO path contains non-ASCII characters, Foundry mirrors the prepared workspace into an ASCII-safe location under %ProgramData%\Foundry\IsoWorkspace and uses %ProgramData%\Foundry\IsoOutputTemp for the intermediate ISO output before copying the final file back to the requested path.

How USB creation works

USB mode is a provisioning workflow, not just a file export:

1. Foundry validates the selected disk identity and confirms it is really a USB target.
2. Foundry warns the operator that the disk will be erased.
3. Foundry repartitions the disk.
4. Foundry formats a BOOT partition and a Foundry Cache partition.
5. Foundry copies the prepared WinPE media to the boot partition.
6. Foundry initializes cache directories for runtime, operating systems, and driver packs.
7. Foundry preprovisions the Foundry.Connect runtime into the cache partition.

Suggested screenshot

Add a capture of the final build action area where the operator chooses Create ISO or Create USB.

Deep dive: USB partition layout

Foundry creates:

• a BOOT FAT32 partition sized for WinPE boot media
• a Foundry Cache NTFS partition for persistent deployment data

The cache partition is where Foundry initializes:

• Runtime
• OperatingSystem
• DriverPack

At boot time, FoundryBootstrap.ps1 looks for the Foundry Cache volume first. When it exists, bootstrap runs in Usb mode and uses that cache-backed runtime root instead of the ISO-backed runtime path.

Partition style and format behavior

USB mode exposes options that do not apply to ISO mode:

• Partition style controls how the USB disk is provisioned.
• Format mode controls whether Foundry uses quick formatting or a full format pass.

ARM64 USB media is more constrained than x64 media. In practice, ARM64 requires GPT in the validation layer.

When to use ISO

Choose ISO when you want:

• a reusable file you can archive or distribute
• virtualization or lab validation
• remote media mounting workflows
• a non-destructive output path

When to use USB

Choose USB when you want:

• a bootable device prepared directly by Foundry
• persistent cache-backed deployment media
• local storage for runtime, operating system, and driver-pack content
• an operator-ready stick for repeated field use

When to switch to expert mode

Use expert mode when you need deterministic control over:

• Network provisioning
• Deployment language visibility and defaults
• Autopilot profile handling
• Machine naming behavior

See Expert Mode for the full breakdown.