Microsoft KB Archive/899855

= The BIOS Real Time Clock is set back one hour after you deploy a Windows XP image or Windows Vista image to a computer =

Article ID: 899855

Article Last Modified on 7/2/2007

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APPLIES TO


 * Microsoft Windows XP Home Edition
 * Microsoft Windows XP Professional
 * Windows Vista Business
 * Windows Vista Enterprise
 * Windows Vista Home Basic
 * Windows Vista Home Premium
 * Windows Vista Ultimate

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SYMPTOMS
After you use the System Preparation (Sysprep.exe) tool to deploy a Microsoft Windows XP image or a Windows Vista image to a client computer, the Basic Input/Output System (BIOS) Real Time Clock (RTC) on the client computer is set back one hour.



CAUSE
This issue occurs if either of the following conditions is true:  The BIOS cannot interpret the time zone to which the RTC is set. The RTC keeps on ticking even when the computer is turned off. When the computer is turned on again, the computer displays the right time. When the System Preparation image comes up, the operating system reads the clock. The operating system then applies the time zone that the operating system was last configured to use. The operating system assumes that the RTC represents the last time that the operating system adjusted the clock. If the following conditions are true, the computer adjusts the clock when the computer starts:  The computer was off before the daylight-saving time (DST)/standard daylight time (SDT) boundary was reached. The computer is now on the other side of the DST/SDT boundary.

The Windows XP image or the Windows Vista image that is described in the &quot;Symptoms&quot; section was created when the BIOS was set for DST and the daylight-saving time option was enabled. When the image starts for the first time in SDT, the DST/SDT boundary code adjusts the clock and resets the current BIOS value. You are using a dual-boot computer. The first operating system adjusts the clock when the operating system starts. When the second operating system starts, the second operating system may adjust the clock again. The second operating system adjusts the clock again because the second operating system does not know that the other operating system has already adjusted the clock.



RESOLUTION
To resolve this issue, use one of the following methods:  Create a new System Preparation image. For more information about how to create a new System Preparation image, visit the following Microsoft Web site:

http://www.microsoft.com/technet/prodtechnol/winxppro/deploy/introductoin.mspx

</li> Make sure that all the computer operating systems are using the correct time.</li></ul>

Keywords: kbtshoot kbsetup kbprb KB899855

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