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Unable to access the UNC paths or shared drives with OfficeScan installed

    • Updated:
    • 24 Nov 2016
    • Product/Version:
    • Core Protection Module 10.5
    • Core Protection Module 10.6
    • Platform:
    • Windows 2003 Enterprise
    • Windows 2003 Enterprise 64-bit
    • Windows 2003 Standard
    • Windows 2003 Standard 64-bit
    • Windows 2008 Enterprise
    • Windows 2008 Standard

With OfficeScan installed, it is possible that some network-related file access via UNC can be blocked. You may experience any of the following:

  • Access to a remote or shared drive cannot be done successfully
  • Cannot copy files to a remote or shared drive
  • Backup software that uses a UNC path cannot complete its operation
  • Access via Windows Explorer to the target UNC path hangs or results to an non-responding window

These file operation issues persist even after performing the standard approach to address them. Procedures include the following:

  • Putting scan exclusions in the backup software's program files and installation directory, target folder or UNC path
  • Disabling of certain OfficeScan features (i.e., Behavior Monitoring)
  • Updating of certain OfficeScan modules to the latest hot fix

Of the above procedures, only OfficeScan uninstallation would improve the situation.


In some cases, the issue could be caused by the Transport Driver Interface (TmTDI). TDI is responsible for interfacing with the network traffic directly.

We recommend doing further isolation for this case. Do the following to confirm if TmTDI is causing the issue:

  1. Disable TmTDI by following these steps:
    1. Remove %SystemRoot%\system32\drivers\tmtdi.sys.
    2. Add a folder in %SystemRoot%\system32\drivers and name it "tmtdi.sys".
    3. Reboot the machine.
  2. After the reboot, unload OfficeScan (if the issue happens even when OfficeScan is unloaded).
  3. Check if TmTDI is not loaded using this command:

    sc query tmtdi

    The STATE should be STOPPED.
    If the STATE is not STOPPED, verify if steps 1 and 2 are performed correctly.

  4. Try to replicate the step and see if the issue occurs.
  5. After the test, remove the folder "tmtdi.sys" created in action and reboot.

    OfficeScan will go back to normal.

If TmTDI is found to be the cause of the issue (issue does not occur with sc query tmtdi = stopped), then do the following:

  1. Open a command prompt and run as administrator.
  2. Enter this command:

    netsh int tcp set global chimney=disabled

  3. Reload the OfficeScan client.

If the issue persists, use the Case Diagnostic Tool and generate logs pertaining to Scanning Issues and to Basic Information.

Solution Id:
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