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Explorer.exe hangs and Network Discovery RRS feed

  • Question

  • Hi there

    We have a weird issue on our two TS 2008 servers (also running Citrix XenApp 5.0).  At logon, a folder is automatically opened for all users, which contains shortcuts to all the apps the users use - we call it the "Program Manager" and use it simplify things for our users, many of whom are not very IT-literate.  Since moving from Windows 2000 TS to 2008, we have an issue where the explorer.exe process hangs, and the start menu and taskbar lock up for 20 - 40 seconds, if the "Folders" section of the Navigation Pane is displayed when the Program Manager folder opens.  If I minimise the Folders section so that only the "Favourite Links" section is visible, and log off/on, the problem goes away.  I am certain that this is causing the Explorer lock-ups.

    Ok so a few questions:-
    1. How does Windows 2008 build the list of PC's on the network to show under "Network"?  Does it exclusively use the Network Discovery feature in 2008?
    2. Is it possible to prevent Windows Explorer from discovering all the PC's and showing them under Network without disabling Network Discovery?
    3. Is there any way to disable Network Discovery without enabling Windows Firewall (which we aren't using on any of our servers)?  I see there are two group policy settings called "Turn on Mapper I/O (LLTDIO) driver" and "Turn on Responder (RSPNDR) driver" under "Link Layer Topology Discovery" - would these do the trick?
    4. Are there any adverse side-effects of disabling Network Discovery or dependencies we should be aware of before tryin this?
    thanks
    Raymond
    RayDiack
    Tuesday, October 6, 2009 10:11 AM

Answers

  • Hello Raymond,

     

    Thanks for posting in our forum.

     

    Based on your description, I understand the issue you encountered as below:

     

    ·          You have two Windows Server 2008-based Terminal Servers in the environment. When a user log onto the system, it is expected that a folder with many shortcuts open;

    ·          If the Folder panel based in the Windows Explorer is displayed, the Windows Explorer (explorer.exe) will hang for 20-40 seconds. If the Folder panel is minimized, the issue doesn’t occur.

    The Network Discovery feature of Windows Server 2008 relies on the WS-Discovery Protocols, which differs from the previous versions. This critical change leads to the performance differences of Network Discovery feature among versions of Windows. However, this change won’t cause the different performance results between local user and terminal users, based on my tests.

     

    In such a case, I highly recommend you to narrow down the problem’s scope, in order to judge if the root cause is related to the network performance or Terminal Services. To do that, please check if the hang issue occurs with local logons: if the problem is the same in such logons, we can exclude the factors from TS side.

     

    Regarding the Question 2-4 in your post, I recommend you to consider the following workarounds:

     

    1.     Disable the Network Discovery from the Terminal Server side. It will stop the computers to discover and list network computers and devices, in the same while the Terminal Server cannot be detected in the network by other computers either. It won’t affect the shared folders or printers to be used. But this workaround requires the Windows Firewall enabled. Besides, I highly recommend you to enable a firewall to protect your Windows Server, in order to avoid security risks.

    2.     Use desktop shortcuts instead of the shared folder. This workaround could avoid opening the Windows Explorer or touching the Network Discovery.

    3.     Educate the user to minimize the Folder panel. This configuration will be kept and the issue won’t occur next time the user logs on.

     

    Based on my tests, the two policy settings under the Link Layer Topology Discovery cannot change the original behavior.

     

    Please let me know if any workaround above is acceptable. If not, or you have more questions on this topic, I’d like to go on helping you troubleshoot this issue.

     

    Thanks for your cooperation and I’m looking forwards to hear you again. Wish you a nice day.

     

    Lionel Chen

    TechNet Subscriber Support in forum

    If you have any feedback on our support, please contact EMAIL REMOVED

    • Marked as answer by Raymond Diack Friday, October 23, 2009 7:04 AM
    Wednesday, October 7, 2009 7:59 AM
  • Hello Raymond,

     

    Thanks for your feedback.

     

    Based on this update, we can narrow down the scope to be Network Discovery performance related, because the issue occurs on all scenarios rather than remote users’ scenarios or logon script dependent. Please correct me if I misunderstood anything.

     

    Regarding your requirement to hide the Folder section in the Windows Explorer from server side, I’m afraid I cannot find any policy settings or registry methods that work on it. On the other hand, Disabling the automatic Network Discovery in Windows Explorer requires Windows Firewall enabled. Therefore, it’s still recommended for you to consider the workaround above, that you can add logon script to update the shortcuts from the shared folder to the desktop. To do that, please create a .BAT-based logon script for all the terminal users, this logon script can include the following key command-line:

     

    COPY %userprofile%\Desktop\*.*  \\<backup folder>\

    DEL %userprofile%\Desktop\*.*  /q

    COPY \\<Central Shared Folder>\*.* %userprofile%\Desktop\*.*  

     

    By this script, you will back up the current desktop content to a backup folder and synchronize the content between the desktop folder and the central shared folder (Program Manager). I think it could ease the management in your case and hold the same shortcuts as the shared folder does.

     

    Please feel free to follow up here and let me know if I can provide any further assistance. Thanks.

     

    Lionel Chen

    TechNet Subscriber Support in forum

    If you have any feedback on our support, please contact tngfd @ microsoft.com

     

    Friday, October 9, 2009 10:29 AM

All replies

  • Hello Raymond,

     

    Thanks for posting in our forum.

     

    Based on your description, I understand the issue you encountered as below:

     

    ·          You have two Windows Server 2008-based Terminal Servers in the environment. When a user log onto the system, it is expected that a folder with many shortcuts open;

    ·          If the Folder panel based in the Windows Explorer is displayed, the Windows Explorer (explorer.exe) will hang for 20-40 seconds. If the Folder panel is minimized, the issue doesn’t occur.

    The Network Discovery feature of Windows Server 2008 relies on the WS-Discovery Protocols, which differs from the previous versions. This critical change leads to the performance differences of Network Discovery feature among versions of Windows. However, this change won’t cause the different performance results between local user and terminal users, based on my tests.

     

    In such a case, I highly recommend you to narrow down the problem’s scope, in order to judge if the root cause is related to the network performance or Terminal Services. To do that, please check if the hang issue occurs with local logons: if the problem is the same in such logons, we can exclude the factors from TS side.

     

    Regarding the Question 2-4 in your post, I recommend you to consider the following workarounds:

     

    1.     Disable the Network Discovery from the Terminal Server side. It will stop the computers to discover and list network computers and devices, in the same while the Terminal Server cannot be detected in the network by other computers either. It won’t affect the shared folders or printers to be used. But this workaround requires the Windows Firewall enabled. Besides, I highly recommend you to enable a firewall to protect your Windows Server, in order to avoid security risks.

    2.     Use desktop shortcuts instead of the shared folder. This workaround could avoid opening the Windows Explorer or touching the Network Discovery.

    3.     Educate the user to minimize the Folder panel. This configuration will be kept and the issue won’t occur next time the user logs on.

     

    Based on my tests, the two policy settings under the Link Layer Topology Discovery cannot change the original behavior.

     

    Please let me know if any workaround above is acceptable. If not, or you have more questions on this topic, I’d like to go on helping you troubleshoot this issue.

     

    Thanks for your cooperation and I’m looking forwards to hear you again. Wish you a nice day.

     

    Lionel Chen

    TechNet Subscriber Support in forum

    If you have any feedback on our support, please contact EMAIL REMOVED

    • Marked as answer by Raymond Diack Friday, October 23, 2009 7:04 AM
    Wednesday, October 7, 2009 7:59 AM
  • Hi Lionel

    Thanks very much your reply.  I have logged on to the server using two different test users, but logging on via the server "console" rather than via Citrix.  I say "console" because in my understanding there aren't really console (or "admin") sessions for RDP like there were with Windows 2003 (i could be wrong though).  For both users, I could reproduce the hanging problem when opening the network folder, with the "Folders" panel open. 

    I'm not too keen to enable Windows Firewall as our standard has been to disable it on all servers, as we have a corporate firewall, antivirus, fairly locked down workstations, current patching via WSUS etc.  If this is the only option though we'll consider it.

    While desktop shortcuts are an option, I'd prefer not to go this route as it means if we add/remove applications/shorcuts, then we need to remember to update the desktop on the Citrix servers.  It's easier for us to have one folder so any changes can be made centrally.  Also, this would hide the problem rather than solving it.  Your suggestion sparked an idea though - I logged on using one of the test users, and opened up a different network share - one containing around 10 text files - so an almost empty share.  The explorer.exe hang still occurred, when the Folders panel was open.  I then tried logging off/on, and then just opening up Windows Explorer, and clicking on "Network".  Again, explorer.exe locked up.  I was hoping that maybe the problem was specific to that specific share (the "Program Manager") but it seems not - seems any Explorer window is badly impacted by Network Discovery.

    Educating the users may work in the short term - but as users leave / new employees join, we don't want to have to keep reminding everyone what to do.  The users are not technical, and so we need to solve all technical issues for them.  Is there no way to automate setting the folder view settings for users for all folders, to always minimise the "Folders" list?  The problem only seems to occur within the first few minutes of logging on, so if we could change the default view for everyone at logon, it should give the server enough time to sort itself out in terms of Network Discovery so that explorer.exe behaves itself.

    Surely this is a bug in Windows?  I've tried using Process Monitor to track down where it's going wrong, but even having filtered events just for the user, and just for explorer.exe, I'm battling to narrow it down.

    thanks
    Raymond
    RayDiack
    Thursday, October 8, 2009 10:12 AM
  • Hello Raymond,

     

    Thanks for your feedback.

     

    Based on this update, we can narrow down the scope to be Network Discovery performance related, because the issue occurs on all scenarios rather than remote users’ scenarios or logon script dependent. Please correct me if I misunderstood anything.

     

    Regarding your requirement to hide the Folder section in the Windows Explorer from server side, I’m afraid I cannot find any policy settings or registry methods that work on it. On the other hand, Disabling the automatic Network Discovery in Windows Explorer requires Windows Firewall enabled. Therefore, it’s still recommended for you to consider the workaround above, that you can add logon script to update the shortcuts from the shared folder to the desktop. To do that, please create a .BAT-based logon script for all the terminal users, this logon script can include the following key command-line:

     

    COPY %userprofile%\Desktop\*.*  \\<backup folder>\

    DEL %userprofile%\Desktop\*.*  /q

    COPY \\<Central Shared Folder>\*.* %userprofile%\Desktop\*.*  

     

    By this script, you will back up the current desktop content to a backup folder and synchronize the content between the desktop folder and the central shared folder (Program Manager). I think it could ease the management in your case and hold the same shortcuts as the shared folder does.

     

    Please feel free to follow up here and let me know if I can provide any further assistance. Thanks.

     

    Lionel Chen

    TechNet Subscriber Support in forum

    If you have any feedback on our support, please contact tngfd @ microsoft.com

     

    Friday, October 9, 2009 10:29 AM
  • Hello Raymond,

    How's going with the case? Please don't hesitated to contact me if I can offer further helps in this issue.

    Thanks and wish you a nice day.

    Lionel Chen

    TechNet Subscriber Support in forum

    If you have any feedback on our support, please contact tngfd @ microsoft.com

    Tuesday, October 13, 2009 7:54 AM
  • Hi Lionel

    Thanks for your reply - sorry I've taken a while to respond - I've been on leave this past week.  Thanks for your suggestion of scripting copying of the shortcuts at logon to the user's desktop.  I think I will first look at enabling Windows Firewall.  It seems that on installation, Citrix XenApp added a whole lot of rules to the firewall config which should make it fairly easy to enable the firewall without breaking access to Citrix/TS.

    I will let you know how it goes.

    thanks!
    Raymond

    RayDiack
    Thursday, October 15, 2009 5:16 PM
  • Hello Raymond,

    It's nice to hear from you again.

    Please let us know the result after the test. I'm glad to provide further assistance any time.

    Have a good day.

    Lionel Chen

    TechNet Subscriber Support in forum

    If you have any feedback on our support, please contact tngfd @ microsoft.com

    Friday, October 16, 2009 1:44 AM
  • Hi Lionel

    Many thanks for your help!  Network Discovery does indeed cause explorer.exe to hang.  I enabled Windows Firewall last night on both our XenApp servers to disable Network Discovery, and the problem has disappeared.  Thanks for your suggestions and assistance!  :)

    take care,
    Raymond
    RayDiack
    Friday, October 23, 2009 7:07 AM
  • Hello Raymond,

     

    Thanks for your feedback. I’m so glad to hear the issue has been resolved.

     

    It’s my pleasure to help you for the troubleshooting process. Please feel free to post in our forum in future, we are always ready to provide assistance based on your needs.

     

    Thanks for your cooperation and patience. Have a nice day.

     

    Best Regards,

    Lionel Chen

    Friday, October 23, 2009 10:48 AM
  • Cool Lionel, thanks again you've been a great help.

    regards
    Raymond
    RayDiack
    Friday, October 23, 2009 11:02 AM