Changing between summer and winter time

When using a write filter, it is not possible to use the automatic summer time / winter time switching function. The reason for this is that, when a write filter is activated, Windows has no possibility to save the information that a time change has been made.

As a result of this, the time is changed back to the respective time offset between winter and summer time after each restart following a time change. This means that if the write filter was activated in the summertime, the time in wintertime will be increased by one hour after each restart.

Solution in the case of EWF and FBWF

With the CXID service there is a possibility to counteract this behavior. In an earlier version this could be done by means of making entries in the registry and "committing" the respective write filter, then restarting the system.

From version 3.1.4.0 of the CXID tool, the DST patch has been revised and its use simplified. Here, the settings can be made by calling the CXID tool via the command line or by script. No entries need to be made in the Registry and no restarts need to be carried out.

In order to switch the DST patch on or off, the CXID tool is called with the following parameters:

Switch the DST patch on:

cxid -enabledst

Switch the DST patch off:

cxid -disabledst

The CXID service can be updated or retrofitted on older systems. The minimum requirement is the Microsoft VCRedist2005 runtime.

• When updating, the CXID service in the Windows\System32 folder must be replaced. When doing so, it must be ensured that the CXID service has been stopped.
• If the CXID service is reinstalled, it must be copied into Windows\System32 and registered via the console with cxid -service.

Solution in the case of UWF

In the case of UWF, the following registry keys must be set instead of the CXID tool:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation