Blog Post:

Fix Enhanced Write Filter: Failed getting protected volume configuration

Windows Embedded 7 EWFI have been working with Windows Embedded Standard 7 (WES7) for quite a while for various projects. In most configurations, the WES7 resides on a SD card with Enhanced Write Filter turned on for System partition. In order to clone the SD cards with the system image, I do sector by sector copy and everything works on the cloned SD card.

However at one point, I had to do setup WES7 on Hard disk and image it. Now when I cloned the hard disk image to other hard disks, the Enhanced Write Filter wouldn’t work on the cloned Hard disks. When I issued the following ewfmgr command

– ewfmgr c:

I would get the following result:
– Failed getting protected volume configuration with error 1.

I tried various cloning software utilities without any success. After hours of troubleshooting, the solution that worked for me was to go to the following registry key:
– HKEY_LOCAL_MACHINESYSTEMCurrentControlSetservices
EwfParametersProtectedVolume0

and change the value of DiskSignature to the disk signature of the disk running WES7.

Missing [HKEY_LOCAL_MACHINESYSTEMCurrentControlSet servicesEwfParameters] key

In another case, after deploying fresh WIM image of WES7, I didn’t get the [HKEY_LOCAL_MACHINESYSTEMCurrentControlSetservicesEwfParameters] key to begin with. In this case I exported the key from another WES 7 installation and imported it in the new installation. Following are the contents of the exported .reg file.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSet
servicesEwfParameters]

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSet
servicesEwfParametersProtected]

[HKEY_LOCAL_MACHINESYSTEMCurrentControlSet
servicesEwfParametersProtectedVolume0]
"DiskSignature"=dword:326b0b32
"PartitionOffset"=hex(b):00,00,10,00,00,00,00,00
"CompareBeforeAlloc"=dword:00000000
"Type"=dword:00000002
"Enabled"=dword:00000000

After importing the key, I fixed the disk signature, restarted the WES7 system and found EWF to be working.

2 Responses

  1. hello, greetings, I use the filter on windowsXP and it works very well, but I need to use it on W7 and I’m not getting it, do I have to use other files? or would it just be modifications to the keys? could you help me please, i am very grateful.

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