Enhanced Write Filter (EWF)

CURRERA running Windows Embedded Standard 2009(R) or Windows Embedded Standard 7(R) can use the Enhanced Write Filter to protect System Disk from write access.


EWF provides the following benefits:
  • Prolongs lifetime of System Disk by controlled writing
  • Offer user better control over system configuration (changes are commit only on demand)
  • Make start of system faster

Operation Modes

EWF can be in one of two modes:
  • EWF Enabled
    In this mode - all writes to disk C: are cached in RAM.
    They are not stored to System Disk.
    To write changes from RAM to System Disk, Commit C: changes should be done before system is restarted.
    • You can commit cached changes (by Commit and restart)
    • You can discard cached changes (by restart)
    • You can disable EWF and restart
  • EWF Disabled
    In this mode - all writes to disk C: are stored to System Disk like to Hard drive on common PC.
    • You can keep this mode and restart
    • You can enable EWF and restart


Controlling of EWF can be done from:
  • Using SSD Control Tool
  • Command prompt (Start/Run/Cmd, enter following commands in opened command window)
    • To commit changes
      ewfmgr c: -commit
      shutdown -r -t 0
    • To discard changes
      shutdown -r -t 0
    • To enable EWF
      ewfmgr c: -enable
      shutdown -r -t 0
    • To disable EWF
      ewfmgr c: -commitanddisable
      shutdown -r -t 0