Preserving power configuration settings during SysPrep.

Manufacturers and system administrators might want to disable the automatic customization of power policy for mobile PCs if they are providing manufacturer-specific or corporation-specific updates to power policy.

The Specialize configuration phase of Windows Setup typically occurs when the system is first started by the customer immediately before the out-of-box experience (OOBE). Therefore, any manufacturer-specific or corporation-specific modifications to power policy that are made before Sysprep has been started or during Audit mode might be overwritten by the automatic customization of power setting defaults for mobile PCs.

Manufacturers and system administrators can disable the automatic customization of power policy for mobile PCs by changing the value of the CustomizeDuringSetup registry value. This ensures that Windows Setup does not modify power policy customizations made by manufacturers or system administrators when installing Windows on a mobile PC.

To disable the automatic customization of power policy for mobile PCs, set the CustomizeDuringSetup registry value to zero (0).

For more information see the following:
https://www.microsoft.com/whdc/system/pnppwr/powermgmt/pmpolicy_vista.mspx