First published on TECHNET on Mar 06, 2007

Q: My machines are missing entries for specific time zones from the registry.  What do I do?

A: When a machine is in the state of missing a time zone key the installation of 931836 will result in the missing key structure being restored, but not the original data.

Applications that expect all time zone keys to contain data may begin returning errors when in this state.   See below for additional details.


On some Windows XP SP2 and Server 2003 SP1 machines, individual registry entries within the Time Zone database key may be missing.

For example:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mountain Standard Time

It is important to note that there is no operational reason for any of the Time Zone keys to removed from a system, and doing so is not recommended or supported by Microsoft.

The 931836 update does not contain values that were not changing, such as the “Display” and “TZI” entries for Mountain Standard Time.
It does however contain a sub key with data under “\Dynamic DST”.
As a result of the registry key creation process used during installation, the “\Mountain Standard Time” key in the hierarchical structure is added back in order to support addition of the “\Dynamic DST” key beneath it, but the original values are not.


In the case where only a single key is confirmed to be missing, it can be exported from a known good reference machine of the same OS version, and then imported to the problem (target) machine.   For multiple keys reference KB 914387 as noted further below.  This information applies to both Windows XP and Windows Server 2003.

Single key: Process using Regedit with machines of the same language

1.       From a known good reference machine where KB 931836 is applies, launch Regedit (Start -> Run -> Regedit) and navigate to the key to be replaced, such as
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mountain Standard Time

2.       Export the key using File -> Export and entering a filename (c:\mst.reg)

3.       Open the newly created file with a text editor such as notepad to confirm the correct key and all contents are present.

4.       Close the file when contents are confirmed and transfer it to the target machine.

5.       Double click the .REG file on the target machine, then answer Yes to add the data in to the registry.

Single key:  Command line process using Reg.exe with machines of the same language

1.        From a command prompt on the reference machine, execute the REG command using the specific key to be exported as seen in the example below:
REG EXPORT "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mountain Standard Time" C:\MST.REG

2.       Copy the file to the target machine, or to a location accessible from the target machine and use REG to import the file:

Single key: variation for transfer from English to non-English operating system

1.        Using either of the processes above, first uninstall KB 931836 from both machines.  This can be done from a command prompt using the following command:
%windir%\$NtUninstallKB931836$\spuninst\spuninst.exe /quiet

2.       Repeat the steps to export the key in question and import to the target machine

3.       Reinstall KB 931836 to both machines, using the appropriate language version of the update on the target machine.
This process will allow the data to be transferred properly and the appropriate strings localized on the target machine.

Multiple keys confirmed or suspected to be missing/ inaccurate

Follow the guidance noted in the “ How to configure the daylight saving time settings ” section of KB 914387. .  The registry file built from this article contains the complete Time Zone information database key for Windows XP and Server 2003.