# Virtual ODD (ISO)

<details>

<summary>Step 1: Pre-check before use (Important)</summary>

* Are virtual drives enabled? [Mode Configuration](https://help.iodd.kr/bootable-virtual-drive/mode-configuration)
* Are you going to use encryption at the same time? If so, proceed with encryption first. [Encryption Guide](https://help.iodd.kr/aes256-encryption-mini-pro-st-lk/encryption-guide)
* The ISO file must be a bootable file.
* Since IODD works the same as physical ODD, an ISO file that does not boot from an actual ODD will not boot from IODD.
* If your PC only supports UEFI boot, you must boot using the Virtual Drive function. Some motherboards do not support ODD boot.
* Even in special cases (when installing an older OS on the latest generation board), the installation operation may fail due to a driver conflict. In this case, VHD files are mostly bootable and installable.

</details>

<details>

<summary>For macOS Users</summary>

* IODD cannot directly mount DMG/BIN/IMG files or disk images for MAC. Must convert to ISO file.
* You can change it directly in Terminal as shown below:

```bash
# 1. Start conversion (converts DMG to CDR format)
$ hdiutil convert [input.dmg] -format UDTO -o [output.iso]

# 2. Rename extension from .iso.cdr to .iso
$ mv [output.iso.cdr] [output.iso]
```

</details>

***

### **ISO file mount**

1. Prepare the ISO file.
2. Copy the ISO file to the IODD disk.
3. Safe removal and Reconnect, or **Long Press** the **`1`** key for 3 seconds.
4. Select the ISO file from the IODD screen and **Press** **`6`** or **`Enter`**.
   * If it is mounted normally, you can see that the virtual drive is recognized on the desktop or in the Finder.
5. **Save current state:** Reconnecting will bring up the virtual drive in its current saved state by **Pressing** the **`9`** key.
6. **No Booting Required:** If the installation does not require booting, double-click the virtual drive or autorun as it is to execute the operation.
7. **Booting Required:** If you need to boot from a virtual drive, continue with the BIOS settings below.

{% hint style="warning" %}
**File not visible?** Try selecting another partition by **Long Pressing** the **`4`** key (partition selection).
{% endhint %}

{% hint style="danger" %}
**If Virtual Drive is not enabled** Please refer to the [Mode Configuration](https://help.iodd.kr/bootable-virtual-drive/mode-configuration) to enable Virtual ODD.
{% endhint %}

***

### CMOS/BIOS Boot Order Setting

{% hint style="info" %}
Boot setup menus may differ depending on the board manufacturer/chipset configuration.
{% endhint %}

Enter the PC's CMOS/BIOS screen (typically using **`F2`** or **`DEL`** keys during booting).

<figure><img src="https://3026209848-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhmDmKL86eZmYvioTSXe5%2Fuploads%2F58QRze4zke6xLLJUyHTQ%2Fboot-os-entry-1.jpg?alt=media&#x26;token=10af43f1-258c-4362-ac52-083da920b9a5" alt="BIOS Setup Entry"><figcaption><p>Enter BIOS setup to configure boot priority</p></figcaption></figure>

1. **Select the BOOT section:** This may be in a submenu like "Advanced" depending on the manufacturer.
2. **Set Boot Mode:** Set the boot mode to **Legacy** if required.
3. **Set Order:** Select **IODD Virtual ODD Drive** as the first priority in **Boot Order**.

<figure><img src="https://3026209848-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhmDmKL86eZmYvioTSXe5%2Fuploads%2FuvG1D7jONccRlylRD7qM%2FbootOrder2.jpg?alt=media&#x26;token=dd5f8fb4-9092-416c-a5da-f3e164d94ba7" alt="Boot Order Priority"><figcaption><p>Set IODD Virtual ODD as the primary boot device</p></figcaption></figure>

{% hint style="info" %}
**Multi-Lun Support:** Some boards do not support Multi-Lun. In that case, enable only IODD Virtual Drive as the bootable drive (disable other drives in the Boot order).
{% endhint %}

{% hint style="warning" %}
**Legacy/UEFI:** If you are unable to select Legacy/UEFI, please contact the manufacturer or use VHD boot methods.
{% endhint %}

{% hint style="danger" %}
**Important:** To prevent accidental formatting of the IODD during OS installation, **Long Press** the **`3`** key for 3 seconds to enable **Write Protection**.
{% endhint %}

**Save & Exit (usually F10)**

If you have set the correct ISO at the top of the boot order, the PC will boot via the virtual ODD.

* **Windows:** You will be prompted to press a specific key on the boot screen (e.g., F6).
* **Mac:** For Intel or Silicon Macs, refer to Apple's official guide for booting from an external disk.