Windows 10 slow explorer access to remote encrypted files RRS feed

  • Question

  • I have one win 10 pro computer with a directory that is encrypted using standard windows encryption.   When I share that directory to another windows 10 pro computer the access to the files are extremely slow in Explorer and applications.  The remote computer has the security key to access the files from the first computer.

    They are all Intel NUCs running windows 10 pro with the latest 1903 feature updates connected via a gigE wired network.  It was already slower than win 7 with the earlier version of Win 10 Pro.  Now it is totally unusable.

    To open a jpeg file with Photo takes about 16 seconds.   I can run a script to copy the file over and open it locally in less than 1 second.   Something is severely broken in the mechanism for accessing and opening remote encrypted files under 1903.

    Sunday, July 21, 2019 12:45 AM

All replies

  • Hello,

    Please run Network Adapter troubleshooter from Settings app > Update & security > Troubleshoot. See if it helps you.

    Also run System File Checker scan:

    1. Search for 'command prompt' using Cortana or Windows Search.

    2. From results, right click on Command Prompt and select Run as administrator.

    3. Type sfc /scannow command and press Enter key.

    4. Let the command complete and then reboot the machine.

    If issue still persists, perform clean boot:

    Let us know if this helps!

    Microsoft MVP (Windows and Devices for IT)

    Windows Insider MVP

    Windows Help & Support []

    Sunday, July 21, 2019 8:18 AM
  • Currently sfc will detect a false error as indicated in support issue  So it is best you don't recommend running sfc.

    I have already ran DISM and didn't find any issues.   I have multiple machines running WIn 10 Pro.  The problem was annoying before 1903.  With 1903 it is unacceptable.   I also tested a clean installed windows 10 pro (1903) machine and exhibited the same problem.

    Monday, July 22, 2019 6:17 AM
  • Hello,

    A similar problem appeared on the Windows 10 1803 version, but the problem disappeared after updating to the 1809 version. This is the method given in the 1803 version, please try this method to see if it is useful to you.

    Slow network share and document access when using Windows 10 version 1803

    Best Regards,


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    Wednesday, July 24, 2019 6:58 AM
  • I have already tried setting the CacheLifeTime = 0.   This might speed up the directory reading but file access remained extremely slow from apps (i.e. Office or Photos)
    I also tried setting FileInfoCacheLifetime=0 and FileNotFoundCacheLifetime=0 but they didn't help.

    The strange thing is that I wrote a simple script to copy the file locally and open it in the same app and the time went from 16 seconds down to just under 1 sec.   The network mechanism to access remotely mounted encrypted files has changed to be unusable.   My speculation is that the change was made to patch a security flaw in access of remote encrypted files.

    Thursday, July 25, 2019 4:21 AM
  • Hello,

    Your speculation may be right. It is recommended that you wait for a later update or submit this question via the Windows 10 Feedback Hub.

    Best Regards,


    Please remember to mark the replies as answers if they help and unmark them if they provide no help.
    If you have feedback for TechNet Subscriber Support, contact

    Monday, July 29, 2019 3:07 AM
  • I have the same problem.  I have 2 Windows 10 computers on the same workgroup.  One has this terrible performance problem opening an EFS encrypted file on the other.  The other can access encrypted files on the first without performance problem.  The computer with the problem is new.
    Sunday, March 15, 2020 11:18 PM