Programs that manipulate volume blocks during the boot process may cause data loss in Windows Vista or in Windows Server 2003

Programs that manipulate volume blocks during the boot process, either directly or by using the FSCTL_MOVE_FILE control code, may cause data corruption or data loss in Windows Vista and in Microsoft Windows Server 2003. In this case, a drive volume may become unmountable. Additionally, you may be unable to start Windows.

Note Defragmentation programs that perform tasks early in the boot process, before the Autochk.exe program finishes, are one example of the kind of program that may experience this problem.

The versions of Windows that are listed in the "Applies to" section use files in the "VolumeName\System Volume Information" folder to store information that is related to snapshots that are created by the Volume Shadow Copy Service. These files have names that contain the following GUID: When a program alters the location of blocks that are used by these files early in the boot process, data corruption or data loss may occur. This problem may also occur when a program overwrites blocks that are used by these files.

When this problem occurs, you may have to format the hard disk. In this case, you must reinstall Windows. For more information about how to reinstall Windows Vista, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to reinstall Windows Server 2003 R2, visit the following Microsoft Web site:For more information about how to reinstall Windows Server 2003 with Service Pack 2 (SP2), visit the following Microsoft Web site:

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