How to Create a Virtual Machine from an Existing Virtual Hard Disk

Applies To: Virtual Machine Manager 2008, Virtual Machine Manager 2008 R2, Virtual Machine Manager 2008 R2 SP1

This topic describes how to create a virtual machine from a virtual hard disk file that is in the Virtual Machine Manager (VMM) library.


The source virtual hard disk must meet the following requirements:

  • The Administrator password on the virtual hard disk should be blank as part of the Sysprep process. However, the Administrator password for the guest operating system profile does not have to be blank.

  • We recommend that you install virtualization guest services (such as Virtual Machine Additions or Integration Components) on the virtual hard disk.


To create a virtual machine from a virtual hard disk:

  1. On the Actions pane in the Virtual Machine Manager Administrator Console, click New virtual machine.

  2. Complete the New Virtual Machine Wizard.

Wizard Page Action

Select Source

  1. Select the Use an existing virtual machine, template, or virtual hard disk option, and then click Browse.

  2. In the Select Virtual Machine Source dialog box, select the template that you want to use.

Virtual Machine Identity

Configure the following options:

  • Virtual machine name (required). Type a unique name for the virtual machine.

  • Owner (required). The owner must have an Active Directory domain account.

  • Description (optional). Type a description for the new virtual machine.

Configure Hardware

To configure additional hardware for the virtual machine, use the following procedures:

  • Startup Order—Select the order of devices to start the operating system.

  • CPU Requirements—Specify processor requirements for the virtual machine.

  • Memory—Specify the amount of memory to allocate to the virtual machine, and whether to use Dynamic Memory.


    Support for Dynamic Memory was introduced in Virtual Machine Manager (VMM) 2008 R2 with Service Pack 1 (SP1).

  • Floppy Drive—Configure the virtual floppy drive to read a physical floppy disk on the host or to read a virtual floppy disk file stored in the library.

  • Video Adapter—Configure the virtual video adapter for a virtual machine.


    Support for video adapter settings was introduced in VMM 2008 R2 with SP1.

  • DVD or CD Drive—Add a virtual DVD or CD drive to an IDE bus.

  • Virtual Hard Disk—Add a virtual hard disk to an IDE device or a SCSI adapter.

  • Network Adapters—Configure one or more virtual network adapters for a virtual machine.

  • Priority and Availability—Configure the virtual machine's priority for CPU and memory resources on the host. Configure the virtual machine to be highly available.


    Support for memory resource priority was introduced in VMM 2008 R2 with SP1.

Select Destination

Choose between two options:

  • Place the virtual machine on a host. The wizard will continue through all of the remaining wizard pages.

  • Store the virtual machine in the library. The wizard will continue with the Select Library Server wizard page.

Select Host

(Host placement only)

Review the rating for each host to determine the most suitable host on which to deploy this virtual machine.


If many hosts are listed, you can use the Host group, Look for, or Group by fields to display a smaller set of potential hosts.

All hosts that are available for placement are given a rating of 0-5 stars based on their suitability to host the virtual machine. The host ratings are based on the virtual machine's hardware and resource requirements and expected resource usage. They are also based on placement settings that you can customize for VMM or for individual virtual machine deployments. The ratings are recommendations. You can select any host that has the required disk space and memory available. For more information about how VMM rates hosts, see How Virtual Machine Manager Rates Hosts.


In VMM 2008 R2, for hosts that are running Windows Server 2008 R2 or for ESX Server hosts, the ratings that initially appear on the Select Host wizard page are based on a preliminary evaluation by VMM. To see the host rating based on a more thorough evaluation, you must select the host by clicking it.

  1. To see the placement settings that VMM used to rate the hosts, and optionally to change those settings, click Customize Ratings.

  2. To view additional information about a host rating, select the host in the list, and then use the tabs in this section to view the following information:

    • Details -- This tab displays the status of the host and lists the virtual machines that are currently deployed on it.

    • Ratings Explanation -- If a host receives a zero rating, this tab lists the conditions that caused the rating.

    • SAN Explanation -- If a SAN transfer cannot be used to move the virtual machine's files to the host, this tab lists the conditions that prevent a SAN transfer.

If a host has network optimization enabled, a green arrow appears in the Network Optimization column. VMM 2008 R2 allows you to take advantage of network optimization capabilities that are available on Hyper-V hosts that are running Windows Server 2008 R2. For information about network optimization and the hardware that supports it, see the Windows Server 2008 R2 documentation. After a virtual machine is deployed, this feature is displayed only for virtual machines that are deployed on a host that is running Windows Server 2008 R2.

If no host in the list has sufficient disk space to host the new virtual machine, click Previous to return to the Volume Configuration page and either remove or reduce the size of one or more volumes. You can also override the default placement options that VMM uses to calculate the host ratings. Any changes that you make apply only for this virtual machine deployment. For more information about how VMM rates hosts, see How Virtual Machine Manager Rates Hosts.

Select Library Server

(Library only)

Select a library server on which to store the virtual machine.

To view additional information about an available library server, select the server in the list, and then click the following tab:

SAN Explanation -- If a SAN transfer cannot be used to move the virtual machine's files to the library server, this tab lists the conditions that prevent a SAN transfer.

Select Path

Accept the default virtual machine path on the host to store the files associated with this virtual machine. You can also click the down arrow to select a different path, or click Browse to specify a different path on the host. You can also choose the following options:

  • If you selected a path other than an existing default path and want to store other virtual machines on that path, select the Add this path to the list of host default paths check box. For information about how to configure default virtual machine paths, see How to Set Placement Options for a Host.

  • If you chose Store the virtual machine in the library, specify the library server that will store the virtual machine, and then select a path on the available library shares to store the virtual machine's files.

The wizard will continue with the Summary page.

Select Networks

Attach the physical network adapters to either Not Connected or to any of the virtual networks on the selected host.

Additional Properties

(Host placement only)

On the Additional Properties page, accept the default settings or modify these settings as described in How to Configure Automatic Start and Stop Actions for a Virtual Machine.


Review the configuration settings. To change settings, click Previous.

Optionally, click View Script to view (and copy) the Windows PowerShell script that runs this wizard and performs the conversion. All administrative tasks in VMM can be performed at the command line, or they can be scripted. For more information, see Windows PowerShell Scripting in Virtual Machine Manager 2008 (

Optionally, select the Start the virtual machine after deploying it on the host check box.

To begin creating the virtual machine, click Create.

In Jobs view, monitor the progress of the new virtual machine creation job and confirm that the virtual machine is created successfully. If the job fails, review the error message at the bottom of the Jobs pane for information about the cause of the failure and the recommended action to resolve the issue.

See Also


Creating Virtual Machines