Update-OSDeployBootUSB

Refresh existing OSDeploy USB volumes from a selected standard or CA 2023 boot-media tree.

Update-OSDeployBootUSB copies a selected OSDeploy Boot build to existing USB volumes without partitioning or formatting their disks. Use the command to update every connected USB boot volume with a matching label, write build metadata, and optionally refresh OSDCloud content on matching data volumes.

Requirements

Run the function from an elevated PowerShell 7.6 or later session on Windows 11 25H2 build 26200 or later. PowerShell must be installed from the MSI package, and curl.exe must be available in PATH.

The workstation must also have:

• A completed OSDeploy Boot build under C:\ProgramData\OSDeployCore\boot.
• Out-GridView for selecting the build and boot-media folder.
• One or more online USB volumes with the expected boot or data label.
• A working Windows Storage provider.

See Module Setup to install OSDeploy and OSDeploy Boot to create completed boot media.

The function updates every connected USB volume whose label matches -BootLabel or -DataLabel. Disconnect unrelated USB storage that uses the same labels before running the command.

Update Guidance

Use Update-OSDeployBootUSB for a prepared USB drive whose partition layout does not need to change. Use New-OSDeployBootUSB to clear a disk and create the OSDeploy boot and data partitions.

The update copies and overwrites source files but does not mirror the source tree. Files that exist only on the destination remain in place.

Content	Matching label	Destination	Behavior
Selected BootMedia	OSDEPLOY by default	Root of every matching USB volume	Copy the complete source tree and write BootMedia.json.
Local OSDCloud content	OSDCloud by default	OSDCloud directory on each matching USB volume	Check free space, prompt separately for each volume, and copy when approved.

Parameters

All parameters are optional. The function has one parameter set and does not accept pipeline input.

Parameter	Type	Default	Accepted values and behavior
-BootLabel	String	OSDEPLOY	Use from 0 through 11 characters. Every connected USB volume whose file-system label equals this value is updated.
-DataLabel	String	OSDCloud	Use from 0 through 32 characters. Every matching USB volume is considered for the optional OSDCloud copy.
-WhatIf	Common parameter	Not enabled	Perform prerequisite checks, media selection, volume discovery, and free-space checks. Change the AutoRun policy, report gated writes, and still display the OSDCloud ShouldContinue prompt.
-Confirm	Common parameter	Not enabled	Request confirmation for each BootMedia copy, metadata write, and approved OSDCloud copy. The function uses the default Medium impact, so these prompts do not appear under PowerShell's default High preference unless requested. It does not suppress the separate OSDCloud prompt.

Label comparisons use PowerShell's default case-insensitive equality. An empty string passes parameter validation, but a volume is selected only when its provider-returned label equals that value.

Examples

Update USB volumes with the default labels

Select a completed build and boot-media folder, then update every connected USB volume labeled OSDEPLOY. When local OSDCloud content exists, the function also evaluates volumes labeled OSDCloud:

Update-OSDeployBootUSB

Match custom boot and data labels

Update all boot volumes labeled WinPE and offer the optional OSDCloud copy for every data volume labeled WinPE-Data:

Update-OSDeployBootUSB `
	-BootLabel 'WinPE' `
	-DataLabel 'WinPE-Data'

Update only the custom boot label

Use a custom boot label while retaining OSDCloud as the data-volume label:

Update-OSDeployBootUSB -BootLabel 'WinPE'

Confirm each gated write

Request approval for every BootMedia copy, BootMedia.json write, and OSDCloud copy that follows the data-volume prompt:

Update-OSDeployBootUSB -Confirm

Each matching boot volume has two independent confirmation points: one for its file copy and one for its metadata file.

Preview the update

Run both media selectors, discover matching volumes, and report the gated file operations without changing USB content:

Update-OSDeployBootUSB -WhatIf

-WhatIf still sets the machine-wide NoDriveTypeAutorun policy to 0xFF. When local OSDCloud content fits on a matching data volume, the function also asks whether to copy it before ShouldProcess reports that the copy would occur.

Capture native copy output

Capture the standard-output lines emitted by robocopy.exe when a copy runs:

$copyOutput = @(Update-OSDeployBootUSB)
$copyOutput | Set-Content -Path '.\Update-OSDeployBootUSB.log'

The function does not return a status object. No success-stream output is returned when no copy runs or robocopy.exe emits no standard output.

Boot Media Selection

The function selects source content before discovering USB volumes:

1. Search C:\ProgramData\OSDeployCore\boot for immediate child directories containing a bootmedia or bootmedia_ca2023 subdirectory.
2. Sort completed builds by last-modified time, newest first, and open a single-selection Out-GridView picker.
3. Find immediate bootmedia and bootmedia_ca2023 directories in the selected build.
4. Sort those directories by name and full path, then open a second single-selection Out-GridView picker.

The function writes a warning and returns when no completed build exists, either picker is canceled, or no supported boot-media folder is selected. Canceling either selector occurs before the AutoRun policy is changed.

After both selections, the function sets this machine-wide policy value without ShouldProcess protection:

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\NoDriveTypeAutorun = 0xFF

Media Architecture

The command can copy either an amd64 or arm64 media tree and does not convert its architecture. Select media that matches the firmware architecture of the devices that will boot the USB.

bootmedia is the standard media tree. bootmedia_ca2023 contains CA 2023 Secure Boot files when the build was created from compatible imported WinRE content. The second selector chooses one tree; the function does not merge or synchronize both variants on a boot volume.

USB Volume Matching

The function uses the Windows Storage provider to get online disks whose bus type is USB. It excludes disks that report no media, maps their partition access paths to volumes, and filters the resulting volumes by exact file-system label.

Matching is volume-based, not disk-pair based. A boot volume and data volume do not need to reside on the same USB disk to be processed. Multiple matching volumes are handled in drive-letter order.

When no boot volume matches -BootLabel, the function writes a warning and continues to the optional OSDCloud workflow. When no data volume matches -DataLabel, it writes a warning and skips the OSDCloud copy.

BootMedia Update

For every matching boot volume with an accessible drive letter, the function performs two separately gated operations:

1. Copy the selected bootmedia or bootmedia_ca2023 tree to the volume root with robocopy.exe.
2. Serialize the selected build object to BootMedia.json in the volume root.

BootMedia.json records the selected build's ModifiedTime, Name, and workstation Path. The metadata write is independent of the media copy. Declining or suppressing the copy does not automatically suppress the metadata write.

The robocopy.exe options include subdirectories, including empty ones, and exclude junction traversal, $RECYCLE.BIN, and System Volume Information. The command does not use /mir or /purge, so destination-only files are retained.

If the selected source path no longer exists, the function writes a warning, skips all boot-volume updates, and continues to the optional OSDCloud workflow. A matching volume whose drive-letter path is unavailable is skipped.

OSDCloud Update

The optional source is C:\ProgramData\OSDeployCore\OSDCloud. When it does not exist, the function writes an informational message and skips the data-volume workflow.

For each matching data volume, the function recursively totals the source-file sizes and gets the volume's remaining space.

Condition	Behavior
Free space cannot be determined	Write a warning and skip this volume.
Source content is larger than available space	Write the required and available sizes in a warning, then skip this volume.
Source content fits	Display a ShouldContinue prompt containing the source, destination, file count, size, and free space.
User declines the prompt	Write an informational message and skip this volume.
User approves the prompt	Apply ShouldProcess, then copy the source tree to the volume's OSDCloud directory.

The ShouldContinue prompt is separate from -Confirm and appears once for each data volume that has determinable, sufficient free space.

WhatIf and Confirmation

-WhatIf still performs all prerequisite checks, opens both Out-GridView selectors, sets the AutoRun policy, discovers matching volumes, checks paths, totals OSDCloud source files, and checks free space.

BootMedia copies and BootMedia.json writes are reported but suppressed. For each data volume with enough space, the function still displays the ShouldContinue prompt. Approving it causes ShouldProcess to report and suppress the OSDCloud copy; declining it skips that report. No USB content is changed by the gated operations.

Without -Confirm, BootMedia and metadata writes proceed without a PowerShell confirmation prompt under the default confirmation preference. The OSDCloud ShouldContinue prompt still appears once for every eligible data volume and cannot be bypassed with -Confirm:$false. With -Confirm, approved OSDCloud copies receive both the data-volume prompt and the subsequent ShouldProcess prompt.

Output

The function returns no structured result. When a BootMedia or OSDCloud copy runs, native robocopy.exe standard-output lines are written to the success stream as System.String values.

No success-stream objects are returned when selection is canceled, no copy runs, all optional copies are declined or skipped, or -WhatIf suppresses every copy. Host messages, warnings, confirmation prompts, and WhatIf messages are not structured return objects.

See Create an OSDCloud USB for the workflow overview or the Update-OSDeployBootUSB command reference for compact syntax and parameter definitions.