Hello, I'm facing a strange issue during deployment using ManageEngine OS Deployer (v11.4.2516.12).

I'm trying to deploy a Windows 11 image (around 15.9 GB image size, ~120 GB required partition size according to template) to a physical disk that has **over 900 GB of unallocated space** — and yet the system throws this error:

> "Image Deployment Failed - Unable to create the new partition(s) since the target disk's unallocated size (931.51 GB) is lesser than the required size (119.98 GB)."

Obviously this doesn't make sense, and I suspect a bug or a miscalculation in how the OS Deployer handles partition mapping.

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### Here's what I've done step-by-step:

1. Booted into PXE using PXEMedia17 (Media version: 11.4.2516.12)

2. Connected successfully to the OS Deployment server.

3. Selected my template (`Win11_Clean`) which uses the image `Image20`.

4. Deployment preference: **Add as new / Overwrite the partition**

5. Partition config: 3 partitions (C: ~17 GB, Hidden ~500MB, System Reserved ~100MB)

6. Disk Adjustment: Enabled

7. Disk number: 0

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### Before deployment:

I ran `diskpart` manually and did the following:

- `select disk 0`

- `clean`

- `convert gpt`

- exited diskpart

I verified with `list partition` — **no partitions exist**, the entire disk is unallocated and clean.

Still, I get the exact same error.

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### ❗Important Note:

I **intentionally avoided** using the `Completely erase target computer’s partitions and deploy` option — because I have a **separate data partition (Drive D)** on the disk that **I must preserve**.

That’s why I went with `Add as new / Overwrite the partition`, so I could delete the old system partitions manually and let OS Deployer create only the needed system partitions, while **keeping Drive D intact**.

If I didn’t have critical data in D, I could’ve used the full wipe option and I’m sure it would’ve worked — but in this case I need a solution that allows partial deployment into available unallocated space.

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### What could be causing this?

- Is this a bug in how OS Deployer calculates usable space?

- Is there any issue with alignment, media version, or the way diskpart prepares the disk?

Would appreciate any official clarification or workaround.

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### Attached screenshots:

1. The deployment error screen showing 931.51 GB unallocated vs 119.98 GB required

2. Diskpart command window showing disk cleaned and converted to GPT

3. The template settings used in OS Deployer (showing “Add as new” and 3 partitions)

4. Image Details screen for `Image20`