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The Microsoft policy for disk duplication of Windows installations
Article ID: 314828 - View products that this article applies to.
This article was previously published under Q314828
When you deploy a duplicated or imaged Windows installation, it is required that the System Preparation (Sysprep) tool is used before the capture of the image. Sysprep prepares an installation of Microsoft Windows for duplication, auditing, and customer delivery. For Microsoft Windows 2000, Windows XP, and Windows Server 2003, Sysprep is included with the latest service pack Deploy.cab. For later versions of Windows, Sysprep is included with the operating system, and Sysprep is located in the following folder:
Sysprep is responsible for removing system-specific data from Windows, such as the Computer SID. During installation of Windows, a computer SID is computed to contain a statistically unique 96-bit number. The computer SID is the prefix of the user account and group account SIDs that are created on the computer. The computer SID is concatenated together with the Relative ID (RID) of the account to create the account's unique identifier.
The following example displays the SIDs for four local user accounts. Notice that only the last four digits are incremented as new accounts are added.
HKEY_USERS on Local MachineCloning or duplicating an installation without taking the recommended steps could lead to duplicate SIDs. For removable media, a duplicate SID might give an account access to files even though NTFS permissions for the account specifically deny access to those files. Because the SID identifies both the computer or domain and the user, unique SIDs are necessary to maintain support for current and future programs. For more information about issues that might occur if you clone an installation of Windows 8 or of Windows Server 2012, go to the "Windows 8 and Windows Server 2012 specific information" section.
S-1-5-21-191058668-193157475-1542849698-1000 User 1a
S-1-5-21-191058668-193157475-1542849698-1001 User 2
S-1-5-21-191058668-193157475-1542849698-1002 User 3
In addition to the computer SID, many other components and features must be cleaned up, generalized, or specialized in order to be imaged. Some examples include the following:
Note This is not a comprehensive list.
We support the following operating systems that are prepared by using the Sysprep utility and then imaged:
Note If an image was created without using Sysprep, we do not support the running of Sysprep after the image is deployed as a way to bring the computer back into compliance. Sysprep must be run before the capture of the image.
If you clone a Windows 8 or Windows Server 2012 image or virtual machine without running sysprep.exe /generalize, P2V and keep the physical computer up and running or create a backup of a computer but keep the original computer running you may experience issues in which push notifications do not work. For example, you may experience the following issues:
To resolve these issues, use one of the following methods:
For more information about the Windows System Preparation Tool, visit the following Microsoft websites:
Windows System Preparation ToolWindows Server 2003
What Is Sysprep?Windows 7
The Windows Automated Installation Kit (AIK) for Windows 7Windows 8 and Windows Server 2012
Windows Automated Installation Kit for Windows 7 documentation (May 2010 Update)
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.
Article ID: 314828 - Last Review: November 21, 2012 - Revision: 8.1