How to Configure Windows Virtual PC Settings in Windows 7

In our previous articles we discussed about how to work with Windows Virtual PC. In this article I will continue our series about this tool and show you what configuration settings are available, what they do and how to modify them.

Where to Find Windows Virtual PC Settings

In order to modify the Windows Virtual PC settings, you have to open the Virtual Machines folder. You can do this simply by searching for "virtual pc" in the Start Menu search box or by going to Start Menu -> All Programs -> Windows Virtual PC and clicking on Windows Virtual PC.

In the Virtual Machines folder you will see all the virtual machines that you have installed on your system and a few details about them: name, status, memory and hard disk location. Select one of them, for example Windows XP Mode.

Now, on the menu bar there are two new buttons: Open and Settings. Click on the Settings button to view and modify the Windows Virtual PC settings for the selected virtual machine.

NOTE: In order to successfully edit Windows Virtual PC settings, the status of the virtual machine has to be Powered down. If it is open, some of the settings will not be saved.

Modify the Name of the Virtual Machine

In the Settings window, click on the Name field and edit its name. Also, you can enter some notes relevant for the virtual machine.

Increase Reserved RAM Memory

The second setting that you can modify is the Memory (RAM) used by the virtual machine. If you click on the Memory field you will see on the right side, the currently allocated memory. You can change this by typing the amount you desire to use.

For Windows XP Mode, the default is 512MB. If you want it to be faster when using multiple applications I recommend you to increase it to 1024MB or 1500MB, depending on the amount of free memory that is available on your system. No matter how much you assign, make sure there is enough RAM left for your host operating system as well. One good thing would be to make sure you will still have at least 1 GB free for it to work properly. If you allocate more memory to a virtual machine and very little is left for your host operating system, you will still get bad performance overall.

Create Additional Virtual Hard Disks

You can add a new virtual hard disk or modify the existing virtual hard disk used by your virtual machine. To add a new virtual hard disk, click on Hard Disk 2 from the left side of the Settings window and then click on the Create button from the right side of the same window.

NOTE: All virtual hard disks used by Windows Virtual PC will have the ".vhd" file extension.

First, you have to choose which type of virtual hard disk you want to add: Dynamically expanding, Fixed size or Differencing. The option that we recommend is the Dynamically expanding one because you will have a virtual hard disk drive which will use real disk space only when needed. All the options are thoroughly explain in our previous article, called How to Install an Operating System in Windows Virtual PC. If you are not sure what option to choose, do check it out.

NOTE: Regarding Windows XP Mode, our chosen example, it uses by default a dynamically expanding virtual hard disk. During the installation of the Windows XP Mode the setup process has created a parent disk in 'C:\Program Files\Windows XP Mode\Windows XP Mode base.vhd' and another disk in a custom location that you had to specify. Mine was 'D:\Virtual PC\Windows XP Mode/Windows XP Mode.vhd'. The parent disk, Windows XP Mode base.vhd, has a fixed size and will remain unchanged. All changes made to the Windows XP Mode (like updates, the installation of third party software) will be saved to the differencing disk, Windows XP Mode.vhd. This kind of setup allows advanced users to configure Windows Virtual PC on multiple PCs and use one parent disk, shared over a network, and a local differencing disk that will store all the new content on each PC.

Enter a name for the new virtual hard disk, modify its location if you want, and click on Next.

Now you have to enter the size of the new virtual hard disk. If you have selected the Dynamically expanding option, you have to enter the maximum amount of space that the disk will be allowed to expand. If you have selected the Fixed size you have to enter the size that you want the virtual hard disk to have. You will also see the maximum amount of space that you can enter. Then, click on Create.

NOTE: For the Differencing virtual hard disk you don't have to choose its size because it consists on two virtual hard disks: the parent disk which has a fixed size and the differencing disk which is by default a dynamically expanding disk. The maximum amount of space to which it can expand is defined by the maximum space that it is available on the real hard disk.

For the Differencing virtual disk type you also have one more step. You have to enter the location of the parent virtual hard disk that will remain unchanged. For Windows XP Mode the default location of the Parent Disk is 'C:\Program Files\Windows XP Mode\Windows XP Mode base.vhd'. Then click on Create.

Modify Virtual Hard Disks

To modify a virtual hard disk click on Hard Disk 1, 2 or 3 from the Settings window. Then, on the right side of the window, click on the Modify button.

Depending on the type of the hard disk you will have different options. For a Differencing hard disk type, you will have two options: select the Compact option if you want to reduce the size of the virtual hard disk as much as possible or Merge the virtual hard disk with its parent virtual hard disk.

If the virtual disk type is Dynamic, you can Convert it to a Fixed disk type and vice-versa.

NOTE: The Compact option is not available for Fixed sized virtual hard disks. Also, if you modify a virtual hard disk that has the Undo Disks feature turned on, the Undo Disk will be deleted.

The Undo Disks Feature & When to Use it

The Undo Disks feature allows the changes that are made to a virtual machine to be stored in a separate file which you can later on apply to the virtual machine or discard, leaving the virtual machine as it was. As an example, you can use this feature with Windows XP Mode when you run different test scenarios and you want to return quickly to the default state.

This setting applies to all virtual hard disks attached to the virtual machine. All the changes to a virtual hard disk will be temporarily stored in an undo disk with the ".vud" file extension.

You can enable or disable Undo Disks from the Settings windows. Click on the Undo Disks option and check or uncheck the small checkbox from the right side of the window to enable or disable Undo Disks.

If you ran some changes in the virtual machine, later on you can choose to permanently apply them by clicking on the 'Apply changes' button, or discard them by clicking on 'Discard changes' button.

DVD Drive

The DVD Drive option allows you to decide what kind of drive you want to attach to the virtual machine. You can select None if you don't want any, you can mount a ISO file using the Open an ISO image option or you can simply select a physical drive.

NOTE: If you have a virtual drive on Windows 7 it will appear as a physical drive in the drop-down menu of the 'Access a physical drive' option.

COM ports

The COM ports on a virtual machine are used mainly by advanced or expert users, for debugging purposes. This being the case we will not go further into details about how to use them. It's good to know that an average user will not need to use them.


In the networking section of the Settings window, you can select the number of network adapters that you want to use. By default, you should not need more than one network adapter. Also this will be set as a 'Shared Network (NAT)' which is the standard option when you simply want the virtual machine to use the physical connection of Windows 7 and you don't want any external network access to your virtual machine.

If you have more than one virtual machine you might consider setting an 'Internal network'. This type of network connection provides a communication channel only between the virtual machines. This way you can isolate the virtual machines from all external networks.

The last option is to use a physical network adapter. This way your virtual machine will appear on the network as if it is a physical computer.

To modify the number of the network adapters simply click on the button next to the 'Number of network adapters' and select the number of adapters you want to use.

Then from the drop-down menus select the type of network connection that you want to use.

Integration Features

We already covered the Integration Features in the Boost Performance with Integration Components for Windows Virtual PC article. Head over there if you want to know more about what are the Integration Features, how to enable or disable them and how to use them.

What is Auto Publish?

The Auto Publish feature allows you to add shortcuts of applications installed in the virtual machine to the Windows 7 Start Menu. I recommend to keep this option enabled (especially for Windows XP Mode). This way all the applications that you install in your virtual machines will be accessible from the Windows 7 Start Menu without the need to start first the virtual machine.

Modify the Default Action of the Close Button

If you want to modify this behavior, select Close from the Settings window. Then, from the drop-down menu, you can choose to Hibernate, Shut Down or Turn off the virtual machine. The difference between Shut Down and Turn off is that the Shut Down procedure will safely shut down the virtual machine while Turn off could case data loses because it is the equivalent of pulling the power cord from a physical PC. This option should be used only if the other two are not accessible.

Also, you have the option to be prompted each time about what action to perform when closing a virtual machine.

When you have finished, click on OK.


As you can see from this article, changing the settings of Windows Virtual PC for each virtual machine, including Windows XP Mode, is not a difficult task to handle. If you have any cool tips and tricks or configuration setups in your company or home network that makes use of Windows Virtual PC, don't hesitate to share them with us in a comment.