locked
COM port database in Vista RRS feed

  • Question

  • Greetings!

     

    I used a virtual comport program with Vista.  From what I can find on the MS website, it seems that these port assignments get "locked in" the database.  If you want to use them, even though the original program is gone, there is an error message that the port does not exist, or is in use.

     

    How do you access the database and delete those entries.  I did see a reference to doing this with Win 2000, but I can't figure out how to use the code that was shown?  I am a user, and not a programmer!

     

    The ports do not show up in the Device Manager.

     

    I am unable to use the software as before, so any help would be appreciated.

    Saturday, September 6, 2008 6:50 PM

Answers

  • Hi,

     

    Please open a CMD window, and run the following command:

     

    Set DEVMGR_SHOW_NONPRESENT_DEVICES=1

     

    Then, please selecting “Show Hidden Devices” from the Device Manager. If it still not show the COM ports, This issue is more Windows Driver Kit related, I do not have more information on it.

     

    The easiest way to is delete the ComDB key in the registry to force the system to regenerate the COM port database from zero. Wiping the com port database should probably be avoided. Doing so will mess up other entities such as USB serial, Bluetooth, and other third party drivers/program that use it.

     

    However, I list the ComDB key location.

     

    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\COM Name Arbiter]

     

    For more information about this issue, I suggest you contact this software author or MSDN to address this issue.

     

    Thank you for your understanding.

     

     

    Friday, September 12, 2008 10:35 AM
    Moderator

All replies

  • Hi k5ybx,

     

    In order to resolve the problem efficiently, please confirm the following points first.

     

    1.Please let me know ether virtual comport program name and the download link.

    2.Please let me know the detail error message. “the port does not exist, or is in use” is not enough to troubleshoot this issue.

    3.You said these port assignments get "locked in" the database, which you found on Microsoft website. Could you please let me know the link? What is the “database” meaning?

     

    After I get the reply. I will take a deep research on the problem.

     

    Thanks.  

     

    Wednesday, September 10, 2008 7:52 AM
    Moderator
  • http://msdn.microsoft.com/en-us/library/ms800603.aspx is the address of the Microsoft discussion of the issue.

     

    The virtual comport software is at http://Sourceforge.net/projects/Com0Com.

     

    Error

     

    Cannot open CAT port (COM6)!

    Possibe cause:

     

    This port does not exist or already used by another program.

     

    Cat will be disabled.

    Thursday, September 11, 2008 2:51 PM
  • Hi,

     

    Please open a CMD window, and run the following command:

     

    Set DEVMGR_SHOW_NONPRESENT_DEVICES=1

     

    Then, please selecting “Show Hidden Devices” from the Device Manager. If it still not show the COM ports, This issue is more Windows Driver Kit related, I do not have more information on it.

     

    The easiest way to is delete the ComDB key in the registry to force the system to regenerate the COM port database from zero. Wiping the com port database should probably be avoided. Doing so will mess up other entities such as USB serial, Bluetooth, and other third party drivers/program that use it.

     

    However, I list the ComDB key location.

     

    [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\COM Name Arbiter]

     

    For more information about this issue, I suggest you contact this software author or MSDN to address this issue.

     

    Thank you for your understanding.

     

     

    Friday, September 12, 2008 10:35 AM
    Moderator
  • Thank you!

    Friday, September 12, 2008 1:24 PM