Enhanced Write Filter
Purpose and function
The EWF (Enhanced Write Filter) is a function that is only available for Windows Embedded
operating systems. It provides write protection that can be configured by the user.
The Enhanced Write Filter enables you to boot Windows Embedded Standard from write-
protected media, set write protection for individual partitions, and adapt the file system
performance to meet user requirements (when using memory cards, for example).
EWF can be used to minimize write access to memory cards. This is important because the
write cycles on memory cards are limited due to technical reasons. We therefore recommend
using EWF if you work with memory cards.
EWF is indispensable when HORM or compressed NTFS is used.
Activate only one write filter per partition - otherwise you risk data loss!
EWF and FBWF are preinstalled in the SIMATIC IPC images.
Ensure that only one write filter is enabled on a partition, otherwise you risk data loss!
In Windows Embedded Standard, the Enhanced Write Filter is disabled by default. After the
operating system has been set up, you should back up your date and then enable the EWF.
The following programs can be used to install, enable or disable the EWF:
● SIMATIC IPC EWF Manager
The SIMATIC IPC EWF Manager is preinstalled and included on the supplied USB stick
"Documentation and Drivers". The SIMATIC EWF Manager can be started with an icon in the
system tray on the task bar.
EWFMGR.EXE is called with the command prompt. The following functions are available:
Write-protect drive C: enable
Write-protect drive C: disable
(modified data is transferred)
Modified files on drive C: Accept
Display information about the EWF drive
Operating Instructions, 11/2016, A5E35782395-AB
Commissioning the device and device functions
4.4 Advanced device functions
ewfmgr c: -enable
ewfmgr c: -commitanddisable
ewfmgr c: -commit