What Is Disk2vhd?
Disk2vhd is a free tool that converts a physical hard drive into a Virtual Hard Disk file (VHD or VHDX)—the native virtual disk format used by Microsoft Hyper-V and Virtual PC. The utility runs on Windows Vista, Windows Server 2008, and higher, including x64 systems.
Disk2vhd’s main advantage is performing the conversion on a live, running system. You don’t need to reboot into a special environment or take the server offline. Disk2vhd leverages Windows’ Volume Snapshot capability to create consistent, point-in-time snapshots of the volumes you select while the operating system continues to function normally.
This snapshot-based approach, powered by the Volume Shadow Copy Service (VSS), ensures that the resulting virtual disk contains all files, system configurations, and the exact partition layout of the source disk. Once the VHD/VHDX file is created, you can attach it directly to a new Hyper-V virtual machine, mount it using Windows Disk Management or Diskpart, or convert it for use with VMware or VirtualBox.
Disk2vhd supports two virtual hard disk formats:
- VHD: This is the classic format that offers broad compatibility with older platforms but has a maximum size limit of 2TB.
- CHDX format: Introduced with Windows Server 2012 and supported by Disk2vhd v2.0 and later versions. It raises the capacity limit to 64 TB, delivers superior performance, provides larger block sizes for dynamic and differencing disks, and prevents data corruption caused by power failures through an internal journaling mechanism.
What Is Disk2vhd Used For?
While Disk2vhd is often categorized strictly as a migration tool, its capabilities span a wider range of real-world IT and personal computing scenarios.
- Physical-to-Virtual (P2V) Migration: This is the primary use case. You can move an entire physical server onto Hyper-V, retiring aging hardware while preserving the exact software environment.
- System Backup and Disaster Recovery: You can create a complete, point-in-time backup of your Windows installation as a VHDX file on an external drive. If the original machine fails, you can boot the backup as a VM on any Windows machine with Hyper-V enabled, minimizing downtime.
- Testing and Development Sandboxes: Developers can create an identical virtual clone of a production server to test new software patches, driver updates, or configuration changes without any risk to the live environment.
- Legacy System Preservation: For organizations running critical software on unsupported operating systems (such as Windows Server 2003 or Windows XP), Disk2vhd can encapsulate the entire OS and application stack into a VM, freeing the organization from vulnerable, end-of-life hardware.
- Cloud Migration: The VHD/VHDX files generated by Disk2vhd can be uploaded directly to Microsoft Azure or other cloud platforms as a precursor to a full cloud migration.
Pros and Cons of Disk2vhd
Before integrating Disk2vhd into your workflow, it is worth weighing its strengths and weaknesses against your specific requirements.
Advantages:
- Completely Free: It is part of Microsoft Sysinternals, with no hidden costs or premium tiers.
- Portable and Simple: No installation is required—just download, extract the ZIP file, and run the executable. The GUI is minimal and easy to understand.
- Online Operation: Unlike many legacy converters, it works on a running system, so there is virtually no downtime.
- Trustworthy: Developed and maintained by Microsoft, ensuring compatibility with Windows and Hyper-V.
Limitations:
- Windows Only: Disk2vhd cannot convert Linux or macOS systems.
- BitLocker Incompatibility: It cannot convert encrypted volumes. You must turn off BitLocker and wait for the volume to be fully decrypted before starting the conversion.
- Virtual PC Size Limit: Virtual PC supports a maximum disk size of 127 GB. Disks larger than this threshold will not work with Virtual PC VMs.
- No Native Multi-Hypervisor Support: The tool outputs VHD/VHDX files, which are native to Hyper-V. To use these disks in VMware or VirtualBox, you must manually convert them using a tool like StarWind V2V Converter or QEMU.
- Limited Command-Line Automation: Disk2vhd supports command-line operation, but selected volumes must have drive letters assigned—volumes without a drive letter (such as certain EFI or recovery partitions) cannot be directly specified. For automated scheduling, you will need to combine the command-line tool with Windows Task Scheduler and a batch script. There is no built-in scheduling engine.
- Conversion Speed: The process can be slow for large disks, as it copies all data from the selected volumes.
How to Use Disk2vhd in Windows Server and Windows 11/10/7
This section walks through the entire process, from preparation to a bootable Hyper-V virtual machine.
- Preparation:✎…
- Download the latest version of Disk2vhd from the official Microsoft Sysinternals page: https://learn.microsoft.com/en-us/sysinternals/downloads/disk2vhd
- Make sure the free space of the target location for your VHD/VHDX file is equal to or bigger than the space used on the source drive (recommended an extra 10-15%).
- Pause any anti-virus software, database servers, or other write-intensive applications to minimize VSS snapshot conflicts.
► GUI walkthrough:
Step 1. Launch the Tool. Double-click the executable and accept the license agreement. The main window lists all volumes present on the system, displaying their drive letters, labels, capacities, and free space.
Step 2. Configure the Output Format. In the options area, check the following boxes:
- Use Vhdx: Recommended. Selects the newer, more robust format.
- Use Volume Shadow Copy: Strongly recommended. Ensures a consistent snapshot of the running system. If unchecked, Disk2vhd will attempt a “live” copy, which may lead to inconsistencies.
Leave “Prepare for use in Virtual PC” unchecked for modern environments. This option is only relevant for the long-deprecated Microsoft Virtual PC and is not needed for Hyper-V.
Step 3. The tool displays all available volumes. Then choose the System Reserved partition (if present) and the main system drive (usually C:).
It creates one VHD for each physical disk on which selected volumes reside. It preserves the disk‘s partitioning information but only copies the data contents of the volumes you actually select.
Step 4. Under “VHD File name,” specify the path for the output file. This should be a different physical drive or a network share to achieve the best performance. But don’t save the VHD back onto the volume you are converting.
Step 5. Click the “Create” button. The process will begin, and a progress bar will indicate the remaining time.
Then wait for the process to get finished. If you have large amounts of data to convert, it may take several hours to complete.
► Disk2vhd Command-line (for scripting and automation):
For recurring backups or scripted migrations, Disk2vhd supports command-line operation. The official syntax is:
disk2vhd <[drive: [drive:]...]|[*]> <vhdfile>
*Example: To capture all volumes on the system and save them as a VHD file:
disk2vhd * c:\vhd\snapshot.vhd
*Example: To capture only the C: and E: drives to a VHDX file on an external drive:
disk2vhd64.exe C: E: D:\Backups\ServerC.vhdx
Command-line limitation: When using the command line, each volume you wish to include needs to have a drive letter assigned. Volumes without a drive letter—such as some EFI system partitions or recovery partitions—cannot be directly specified. To include all volumes reliably, use the * wildcard to capture the entire disk. Disk2vhd will create one VHD for each disk that has selected volumes on it.
► Mounting and booting the VM in Hyper-V
Step 1. Open Hyper-V Manager and select “New” > “Virtual Machine”.
Step 2. In the New Virtual Machine Wizard, for Generation, choose Generation 2 if your source machine uses UEFI firmware (common for Windows 8/10/11 and Server 2012+), or Generation 1 for legacy BIOS-based systems (Windows 7, Server 2008).
Note: Microsoft recommends Generation 2 to take advantage of features like Secure Boot and larger boot volumes. Note that once a VM‘s generation is set, it cannot be changed.
Step 3. On the Connect Virtual Hard Disk page, select “Use an existing virtual hard disk” and browse to your newly created VHD/VHDX file.
Step 4. Complete the wizard and start the VM. The first time a captured copy of Windows boots, it will detect the VM’s virtual hardware and attempt to install drivers automatically.
Step 5. After the VM boots, install Hyper-V Integration Services for improved mouse, network, and display performance. In Virtual Machine Connection, go to “Action” > “Insert Integration Services Setup Disk” and follow the prompts.
Note: Do not attach the VHD to the same system on which you created it if you plan on booting it. Otherwise, Windows will assign the VHD a new disk signature to avoid a collision with the source disk’s signature. Since the boot configuration database (BCD) references disks by signature, Windows booted in a VM will fail to locate the boot disk.
Common Error when using Disk2vhd
Even with its simple interface, you may encounter issues during a Disk2vhd operation.
1. “Access Denied” Error (0x80070005):
- Cause: This is one of the most common problems. It typically means Disk2vhd is not running with Administrator privileges, or that security software is interfering with VSS writer callbacks.
- Solution: Ensure you have launched the tool as an admin, and temporarily disable any third-party antivirus or endpoint protection software during the conversion.
2. VSS Errors (“Failed to Create Snapshot”):
- Cause: This indicates a problem with the Volume Shadow Copy Service.
- Solution: Open Command Prompt as an administrator and run vssadmin list writers to check for any writers in a “failed” state. A reboot often resolves transient VSS issues. If the problem persists, check the Windows Event Log for specific VSS error details.
3. Insufficient Space:
- Cause: If the target drive runs out of space, the creation will fail.
- Solution: Always verify that the destination has enough free space—ideally 1.2 times the used space on the source volume.
4. Boot Failure in the VM (INACCESSIBLE_BOOT_DEVICE):
- Cause: This blue screen error typically points to a boot configuration or disk controller issue. The error indicates that the operating system cannot access its boot volume. Common causes include a corrupted BCD, an inactive Windows partition, or a disk controller driver mismatch.
- Solution: Ensure the VM‘s generation (Gen 1 vs. Gen 2) matches the source system’s firmware type and that the boot disk is attached to the correct controller.
5. BitLocker Errors:
- Cause: Disk2vhd does not support the conversion of volumes with BitLocker enabled.
- Solution: Turn off BitLocker from the Control Panel and wait for the drive to fully decrypt before running the tool.
6. I/O Errors:
- Cause: These may indicate bad sectors on the source disk.
- Solution: Run chkdsk /f on the source drive to detect and repair file system errors, then attempt the conversion again.
Alternative to Disk2vhd for Easier P2V Conversion
While Disk2vhd is a solid, lightweight utility for one-off P2V snapshotting to Hyper-V, it isn’t designed for every migration scenario.
If you are managing a complex migration—whether it’s a large-scale data center move, a project that demands true zero-downtime cutover, or a migration to a platform other than Hyper-V, a more comprehensive commercial solution may be a better fit.
One such alternative is i2Migration, a powerful live migration solution developed by Information2 (Info2soft). It uses real-time, byte-level data replication to replicate an entire running system—including the operating system, applications, user data, and network configurations—to a virtual machine without interrupting business operations.
Key capabilities that make i2Migration excellent:
- Real Zero-Downtime Migration: Disk2vhd requires you to shut down the source machine and boot the VM, which always involves some downtime. i2Migration supports Hyper-V live migration without the need to pause your service.
- Cross-Platform and Cross-Hypervisor Flexibility: Disk2vhd only outputs VHD/VHDX files for Hyper-V. i2Miragtion is hardware- and hypervisor-agnostic, supporting migration in any direction: P2V (Physical to Virtual), V2V (Virtual to Virtual), V2P (Virtual to Physical), and P2P (Physical to Physical). It works with VMware, KVM, Citrix XenServer, etc.
- Heterogeneous Hardware Migration: Since i2Migration works at the operating system level and uses hardware-independent replication, you can migrate a system from an old server to a new one with completely different CPU, memory, and storage hardware without worrying about driver incompatibility.
- Incremental Migration: Once the initial synchronization is complete, all incremental data is continuously replicated. You can then schedule a predictable, near-instant cutover to the new machine, keeping downtime to a true minimum.
- Support for Both Windows and Linux: A major limitation of Disk2vhd is its Windows-only scope. i2Miration supports a wide range of Windows (Server 2003R2 to 2022, Windows XP to 11) and Linux distributions (CentOS, Red Hat, SUSE), making it suitable for heterogeneous enterprise environments.
- Automation and Scalability: While Disk2vhd handles one machine at a time with manual steps, i2Migration is built for scale. It offers a centralized management console to handle large-scale migration projects involving hundreds or thousands of servers, with features like bandwidth throttling, data compression, and encrypted transmission with resume-from-breakpoint.
You can click the button below to request a 60-day free trial:
Frequently Asked Questions about Disk2vhd
Q1: Can Disk2vhd be made to create a fixed-size VHD?
A: No, Disk2vhd does not have a built-in option to create a fixed-size VHD. It always produces a dynamically expanding disk that grows as data is written.
If you need a fixed-size VHD — for example, to meet Azure migration requirements — you can work around this using Hyper-V Manager or PowerShell on any machine with the Hyper-V role installed. In Hyper-V Manager, launch the “Edit Disk” wizard, select the dynamic VHD, and on the Action screen choose “Convert” to create a fixed-size copy. Alternatively, you can run the following PowerShell command:
Convert-VHD -Path D:\DynamicDisk.vhdx -DestinationPath D:\FixedDisk.vhdx -VHDType Fixed
Note that the conversion requires free space at least equal to the maximum size of the dynamic disk. Also, Disk2vhd creates one VHD file per physical disk that contains the volumes you select.
Q2: Can I run Disk2vhd in Safe Mode?
A: Yes, Disk2vhd can run in Windows Safe Mode, and it is sometimes recommended as a troubleshooting step. Safe Mode loads only essential drivers and services, which can help you bypass software conflicts — particularly with third-party security or backup applications that may interfere with the Volume Shadow Copy Service (VSS).
If you encounter persistent VSS failures or “Access Denied” errors during a normal conversion, booting into Safe Mode and running Disk2vhd from there can often produce a clean result. Keep in mind that Safe Mode loads a minimal graphics driver, so the GUI will still be accessible.
Q3: Can VirtualBox on Linux use VHD files created by Disk2vhd?
A: Yes, VirtualBox on Linux can use Disk2vhd-created VHD files, but success depends on a few factors:
- Disk format: VirtualBox has native support for VHD files, so in theory, you can attach them directly. However, some users report a VERR_NOT_SUPPORTED error when trying to attach Disk2vhd-generated VHDs. In that case, converting the file to VirtualBox‘s native VDI format using VBoxManage clonemedium or a tool like CloneVDI usually resolves the issue.
- Firmware mode: The most common boot failure happens when the VHD was created from a UEFI-based Windows system (common on Windows 8/10/11), but the VirtualBox VM defaults to legacy BIOS mode. You must go into the VM’s System > Motherboard settings and check “Enable EFI (special OSes only)”. If the source system used legacy BIOS, leave EFI disabled.
- Boot loader conflicts: If the source machine was a dual-boot system with GRUB, the VHD may boot directly into the GRUB menu instead of Windows. This is a known issue and typically requires fixing the Windows boot loader inside the VM using bootrec commands from Windows recovery media.
For best results, capture all partitions (system, boot, and recovery partitions) during the Disk2vhd conversion, and convert the resulting VHD to VDI before use.
Q4: Can you perform an image backup after using Disk2vhd?
A: Yes, there is no conflict between Disk2vhd and Windows image backup tools — they serve different purposes and can coexist in your backup strategy.
Disk2vhd creates a virtual hard disk copy of your physical drive, which is designed to be booted in Hyper-V, VirtualBox, or Virtual PC. In contrast, a traditional system image backup (created through Windows Backup and Restore, wbadmin, or third-party tools) produces a compressed, proprietary file set optimized for bare-metal recovery.
It is perfectly valid to run a system image backup after completing a Disk2vhd conversion, and combining both approaches gives you the most flexibility:
- Use the Disk2vhd VHD for quick P2V migration or instant VM-based recovery.
- Use a system image backup for traditional bare-metal restoration or long-term archival with compression.
The only caution is to ensure your backup destination has enough free space and that you are not writing both backup streams to the same source disk simultaneously, as this will degrade performance.
Q5: Is Disk2vhd able to be used with VirtualBox?
A: Yes, Disk2vhd can be used with VirtualBox. By default, Disk2vhd outputs VHD/VHDX files — Microsoft’s native format for Hyper-V. VirtualBox supports VHD files, but with limitations:
- No VHDX support: VirtualBox cannot read VHDX files at all. If you created a VHDX with Disk2vhd, you must first convert it to VDI or VHD using VBoxManage clonemedium.
- Format conversion recommended: Even for standard VHD files, experienced VirtualBox users and forum moderators frequently recommend converting to VDI for better performance and reliability. Use Mpack‘s CloneVDI tool or the VBoxManage clonemedium command.
- Check firmware settings: VirtualBox defaults to legacy BIOS boot. If the Windows installation inside the VHD was booting via UEFI, go to VM Settings > System and enable the EFI option. If the source system used a legacy BIOS, do not enable EFI.
- Boot issues and recovery: After attaching the VHD and booting, you may see a blue screen due to disk controller driver mismatches. Booting into Safe Mode on the first launch allows Windows to install the necessary drivers. Some users also experience a “turtle mode” where the VM runs extremely slowly until VirtualBox Guest Additions are installed
Conclusion
Disk2vhd remains one of the most valuable utilities in any IT professional ‘s toolkit. Its simplicity, zero-cost price tag, and ability to clone a running Windows system with VSS-backed integrity make it a formidable first choice for physical-to-virtual migration onto Hyper-V.
But for IT teams facing complex, high-stakes migrations, Info2soft’s i2Miration offers a suite of features that go well beyond simple snapshotting. Its real-time replication, cross-platform support, and ability to orchestrate massive, zero-downtime migrations make it a powerful Disk2vhd alternative for mission-critical environments.
By:
