How do I Activate/Deactivate the EWF (Enhanced write filter) on Windows 7?
Issue
File writes or program installation to the main drive of a Magelis iPC are not being kept before and after a restart because the disk volume is write-protected.
Product Line
Magelis iPC, HMIG5U, HMIG5U2, HMIG5U22, Harmony P6
Environment
Windows 7 Embedded
Cause
The main disk volume of the iPC is write-protected in order to maximize the life of the disk as well as ensuring the saved state of the disk for consistent behavior day-to-day for applications which need it (for example a factory HMI). This is done through a feature called the Enhanced Write Filter in Windows 7 (EWF) and the Unified Write Filter in Windows 10 (UWF)
Resolution
Verifying current state of EWF:
- Click on the** Start** button on your PC.
- Please now select the Run option and at the command prompt type** cmd** (make sure there's administrator rights... if not run as administrator)
- You will now be presented with a black command prompt window and within this will need to type – ewfmgr c:
- This will now return a series of results and will tell you the current state of the EWF.
The Windows Taskbar will also indicate the EWF status:
See the screenshot: "Windows Taskbar EWF State.png"
EWFMGR activate and deactivate commands to use:
To use any of the following commands then you will need to firstly navigate to the command prompt window with the following steps:
- Click on the Start button on your PC.
- Please now select the Run option and at the command prompt type cmd
- You will now be presented with a black command prompt window and begin typing the following commands:
ewfmgr.exe c: -Enable
Activates the EWF from the DOS cmd prompt.
ewfmgr.exe c: -Disable
Deactivates the EWF from the DOS cmd prompt.
ewfmgr.exe c: -commitanddisable
Commits changes that exist in the RAM state to the drive, then deactivates the EWF from the DOS cmd prompt
The Graphical User Interface to Activate/Deactivate EWF can also be used (EWF Windows GUI.PNG):
1. Double-click on the padlock icon and the :Enhanced Write Filter: Overview” popup should appear.
2. Select the “C:” row.
3. Click on “Configure…”
4. Select “Disable”
5. Tick the “Commit” Checkbox
6. Click OK
7. Windows Restart windows from the Start bar.
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To Activate/Deactivate the UWF (Unified Write Filter) on Windows 10, please see this FAQ: https://www.se.com/us/en/faqs/FAQ000245569/
If this FAQ did not solve your issue, you can chat with us at chat with us or e-mail us at customer.services@se.com to create a case with our Technical Support Team.
If you are not located in North America, please contact your local Customer Care Center for assistance: