Configuration Manager task-sequence integration

Companion to Invoke-OSDDiskLayout.ps1 (1.0.0). Not field-certified. Use disposable media and a copy of the task sequence for the first tests. In an active WinPE task sequence, running the script without -Preview erases the selected disk. Do not add a native Format and Partition Disk step after it.

Recommended structure

Install operating system / fresh-install branch
Restart in Windows PE
Check Readiness / confirm image and firmware policy (optional)
Run PowerShell Script: Invoke-OSDDiskLayout.ps1
Pre-provision BitLocker (optional, if boot image and policy allow)
Apply Operating System Image -> OSPART
Apply boot-critical and other device drivers
Setup Windows and Configuration Manager
Restart into the installed OS
Validate boot, partition layout, and WinRE

The one PowerShell action replaces every Disk 0, Disk 2, BIOS and UEFI Format and Partition Disk action in the same install path. Do not leave a second formatter enabled or add a fallback formatter after an error. A missing layout result must stop deployment; it must not cause the image to use “next available formatted partition.” For an in-place upgrade, use a different branch: this script never preserves the installed OS.

Before the layout step

Boot the actual ConfigMgr WinPE image with Windows PowerShell 5.1, its dependent WinPE optional components (WMI, NetFX and Scripting), StorageWMI, the Configuration Manager task-sequence runtime and storage drivers. WMF installed in full Windows does not add components to WinPE.
Validate Intel VMD/RST/RAID and Surface Storage Spaces topology in this exact boot image. A missing driver can hide the intended drive or present constituent drives differently. An unusual Disk 2 or Disk 3 is not, by itself, a reason to choose Disk 0.
Keep the task-sequence working data, script package and logs off the target disk. The script checks _SMSTSMDataPath, _SMSTSLogPath and its own path before cleaning; if it cannot establish a safe location, it stops. It does not migrate ConfigMgr’s working directory automatically.
Run any OS-specific hardware checks before the destructive step. A Windows 11-only sequence needs a supported image and separate hardware readiness checks; -RequireUEFI only enforces the firmware mode.
If a custom unattend answer file is enabled on Apply OS Image, inspect its Microsoft-Windows-Setup/DiskConfiguration and ImageInstall/OSImage/InstallTo settings. Do not allow the answer file to repartition a second disk or override the destination selected by the task sequence. Without the answer file’s contents, its safety cannot be inferred from the editor checkbox.

Step 10: Run PowerShell Script

Setting	Recommended value
Name	`Partition selected OS disk (UEFI/GPT or BIOS/MBR)`
Script source	Package containing `Invoke-OSDDiskLayout.ps1`; reference that script by name
Parameters: normal Windows 10 / dual-mode profile	Blank (auto-selects by actual WinPE boot mode)
Parameters: Windows 11-only profile	`-RequireUEFI`
Parameters: legacy BIOS-only OS profile	`-RequireBIOS`
Parameters: approved multi-disk model	Add a tested, unique `-TargetSerial` or cumulative disk-bus/model rule
Execution policy	`Bypass` for an unsigned lab script; use the organization’s signing policy for signed production code
Output to task sequence variable	Blank; the script itself sets `OSPART`, `OSDDiskIndex` and status values through the TS environment
Continue on error	Unchecked
Success codes	Default success only (`0`); do not make a nonzero code successful
Timeout	Verify the configured limit; the step normally defaults to 15 minutes. Adjust only after testing the target hardware
Step conditions	Do not use Disk 0/Disk 2 WMI size queries or a UEFI-only condition on an auto-firmware step

The Parameters box contains only parameters, not a second powershell.exe command or the script filename. For example, a Windows 11-only step has -RequireUEFI there. Do not combine -RequireUEFI and -RequireBIOS.

For a known 32-GB-class legacy disk, the default 64-GB selection floor and 40-GiB Windows minimum are intentionally conservative. Only after testing the actual OS image, an explicit policy might use:

-RequireBIOS -MinimumDiskSizeGB 32 -MinimumWindowsSizeGiB 24

This merely allows planning a smaller partition. It does not ensure adequate free space after setup and servicing. A fixed 120-GiB Windows partition plus a remaining NTFS Data partition instead uses -WindowsSizeGiB 120 -CreateDataPartition. The BIOS Data variant fills the fourth MBR primary slot and blocks a direct future MBR2GPT conversion.

Step 20: optional BitLocker preparation

If the task sequence uses ConfigMgr Pre-provision BitLocker, put it after successful partitioning and before Apply OS Image. The boot image needs its own BitLocker/TPM support (WinPE-SecureStartup). Do not make this a silent side effect of the disk-layout script. If a prerequisite fails, do not use “Continue on error” to mask a failed OS layout.

Step 30: Apply Operating System Image

In the Destination setting select Logical drive letter stored in a variable, then enter OSPART as the variable name (no % characters, no W: literal). The script puts W: in OSPART only after it verifies the chosen disk’s partition style, partition order, Windows filesystem and temporary letter. If -OSPartitionVariable is changed, enter that custom variable name here instead.

Gate Apply OS Image, or the group containing all downstream install steps, on these custom-variable conditions:

DiskLayoutStatus      equals  Success
DiskSelectionStatus   equals  Success
DiskLayoutMode        equals  FreshInstall
OSPART                exists

For a Windows 11-only image also require:

DiskPartitionStyle    equals  GPT
_SMSTSBootUEFI        equals  true

The extra Windows 11 conditions are defense in depth, not a substitute for the layout step’s -RequireUEFI. When BIOS boot is allowed for a compatible image, do not gate this shared install branch on DiskPartitionStyle=GPT.

Keep Continue on error unchecked for Apply OS Image and Setup Windows and Configuration Manager. Never fall back to ConfigMgr’s default “next available formatted partition.” The custom OSDDiskIndex is diagnostic; this script does not hand a disk/partition pair to Apply OS. The built-in OSDTargetSystemDrive is an output of Apply OS Image, not the script’s input or a replacement for OSPART.

Step 40 onward: first boot and validation

Apply storage and other boot-critical drivers before the first boot into the new OS. The disk script cannot install those drivers in the applied Windows image. After Windows setup, validate with reagentc /info and inspect the disk layout: GPT or MBR matches the actual firmware, Windows is installed on the intended disk, and WinRE is enabled and located on the adjacent Recovery partition with enough free space. Creation of a correctly typed Recovery partition alone does not copy or register winre.wim; put any WinRE repair in a separate, validated post-install operation. Do not insert BCDBoot into this partition step without testing the actual ConfigMgr image-application and setup workflow.

Variables and checks

Variable	Meaning / safe use
`_SMSTSInWinPE`	Must be `true` for execution; the script enforces it.
`_SMSTSBootUEFI`	ConfigMgr firmware indicator; the script compares it with `PEFirmwareType` when set and stops on a contradiction. Do not set it yourself.
`OSDMigrateUseHardlinks`	`true` stops this fresh-install script.
`_SMSTSClientCache`	Nonempty client-cache path stops destructive execution.
`_SMSTSMediaType`, `_SMSTSLaunchMode`	OEM media or prestaged hard-disk boot modes stop destructive execution.
`_SMSTSMDataPath`, `_SMSTSLogPath`	Working-data/log locations checked against the selected physical disk.
`OSDTargetSystemDrive`	Apply OS Image output; a pre-existing value stops the disk script.
`OSDDiskIndex`	Selected disk number for diagnostics; do not hard-code it to `0`.
`OSPART`	Verified temporary Windows drive (`W:`); destination variable for Apply OS Image.
`DiskSelectionStatus`, `DiskLayoutStatus`	Both `Success` only after formatting and validation; `Failed` on errors.
`DiskLayoutMode`, `DiskPartitionStyle`	`FreshInstall` and `GPT`/`MBR` after success.
`DiskDataPartitionGuid`	Optional GPT Data partition only; MBR has no GPT partition GUID.

Do not add _SMSTSBootUEFI = true to the parent layout group if the same script is intended to partition both UEFI and BIOS devices. Conversely, if the task sequence applies only a Windows 11 image, an existing enabled BIOS format step must not remain under that image. Passing -RequireUEFI causes an accidental BIOS boot to fail before clean rather than silently skipping the layout step and running Apply OS with stale state. Likewise, do not leave multiple overlapping disk-size WMI conditions that could execute two formatters.

Non-destructive rollout

On a running test computer, use -Preview for a disk inventory and simulated layout. For a BIOS plan from full Windows, add -PreviewFirmware BIOS. Full Windows cannot prove how the WinPE driver stack will enumerate disks.
Run -Preview under the actual WinPE boot image; inside a task sequence it deliberately returns a failing step and sets layout status to Failed, so no Apply OS action should proceed. It emits proposed DiskPart commands but creates no command file and never invokes DiskPart.
Test the actual destructive branch only on a disposable disk, first in UEFI and then in BIOS when that mode is in scope. Verify a sole internal Disk 2/3, ambiguous multi-disk, occupied S:/W:, cached content on target, bad storage drivers and error handling.
Confirm Apply OS Image uses OSPART and inspect the first boot, partition types/attributes and reagentc /info. Save logs before reboot and redact inventory identifiers before sharing publicly.