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The windows snapshot component VSS will fail if a disk with a non standard sector size is attached to your system. This error will occur regardless of whether the disk is a backup source or target. This can be an internal disk or one connected by USB or eSata. The issue is actually caused by USB enclosures that modify the disk drive geometry in the USB to SATA bridge.
See also: VSS fails Fails due to modification by 3rd party software
Applies To
Windows XP,Vista, 7, Server 2003, 2008, 2008 R2.
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