Write Filters and Automatic Adjustment of Daylight Saving Time (Standard 8)


Learn how to turn off Automatic Daylight Saving on your Enhanced Write Filter (EWF)-enabled Windows Embedded 8 Standard (Standard 8) device.

Automatic adjustment of daylight saving time (DST) is incompatible with Enhanced Write Filter (EWF) and File-Based Write Filter (FBWF). If Automatic Daylight Saving is enabled when EWF or FBWF is enabled, the system clock will either fall back or spring forward every time that the computer is restarted.

The recommended approach to solving issues with DST when you use write filters is to change the CMOS clock to use UTC.

To change the CMOS clock to use UTC

  1. Make sure that EWF and FBWF are disabled.

  2. Configure the Windows systems Time Zone to the desired value (for example, Pacific Time Zone).

  3. Add the RealTimeIsUniversal key DWORD value to the registry at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\.

  4. Change the value of the RealTimeIsUniversal key to 1.

  5. Restart the system and go into the BIOS.

  6. Set the CMOS clock to the current UTC time and date. For example, if you are in Pacific Standard Time Zone, and it is 11:00 AM, you would set the CMOS clock to 7:00 PM, as there is 8 hours difference.

  7. Restart the system and enable EWF or FBWF.

See Also


FBWF Integration
EWF Integration
Enhanced Write Filter (EWF) Overview
File-Based Write Filter (FBWF) Overview