# Advanced VHD Tool++ Functions

**VHD Tool++** is a **Windows-exclusive application**. Beyond simple creation, it provides several utility functions for managing virtual drives:

* **\[Convert]**: Converts a general disk dump image file into a fixed-size VHD file.
* **\[Extend]**: Increases the size of an existing fixed VHD file.
* **\[Defragment]**: Specifically defragments a single file on the IODD to ensure it is contiguous (0 fragments).
* **\[Upload]**: Copies a file from your PC to the IODD while ensuring it remains unfragmented during the transfer.
* **\[Write To HDD] (Expert Only)**: Performs a sector-to-sector physical duplication of an image file to the internal HDD. **Note**: This function only supports the **NTFS**, **exFAT** file system.

{% hint style="danger" %}
**WARNING**: This will permanently delete ALL data on the internal drive. It is only recommended for advanced users performing raw disk operations.
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://help.iodd.kr/bootable-virtual-drive/virtual-drive-vhd/advanced-vhd-tool-functions.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.