Error message when you use an Unattend.xml file to install Windows Vista through a .wim file: "Windows could not calculate how much space is required for installation"

You use a Windows Vista-based computer to generate a Windows Imaging Format (.wim) file that contains more than 30 images. When you use an Unattend.xml file to install Windows Vista through the .wim file, the installation fails. Additionally, you receive an error message that resembles the following:

This problem occurs because the Unattend.xml file is too large.

When the .wim file grows, the size of the XML data that describes the .wim file grows. If a .wim file contains 30 or more images, the size of the corresponding XML data increases to more than 64 kilobytes (KB). Therefore, functions that read the XML data truncate some XML data.

Service pack information

To resolve this problem, obtain the latest service pack for Windows Vista. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfixes and security updates that are included in SP2 for Windows Vista Service and for Windows Server 2008

For more information about the hotfixes and the security updates that are included in SP2 for Windows Vista and for Windows Server 2008, visit the following Microsoft TechNet Web site: -Note: Currently, the list of hotfixes and security updates is available only in English.

Hotfix information

A hotfix is available to resolve this problem. To apply this hotfix on an x86-based computer, follow these steps.

Note To apply this hotfix on an x64-based computer, replace x86 with x64 in the commands in steps 1 and 2.

1. Run the following command to expand the .msu file:
   Expand -f:Windows6.0-KB945683-x86.cab Path of the .msu file\Windows6.0-KB945683-x86.msu Path of the destination file
2. Run the following commands to expand the .cab file:
   Expand -f:*.exe Path of the .cab file\Windows6.0-KB945683-x86.cab Path of the destination file
   Expand -f:*.dll Path of the .cab file\Windows6.0-KB945683-x86.cab Path of the destination file
   After you run these commands, you will obtain some .exe and .dll files.
3. Use the files that you obtain in step 2 to overwrite the original files in the InstallPoint\Source folder.
   
   Note InstallPoint is a placeholder for the location of the contents of the Windows setup media.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

There are no prerequisites for installing this hotfix.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows Vista, x86-based versions

Windows Vista, x64-based versions

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: