Way High Serial Port Numbers

Archived from groups: microsoft.public.windowsxp.hardware (More info?)

I frequently install and remove modems and multi-port I/O cards in my XP Pro
system. The Comm port numbers grow, and now my modem is Comm 14. My
software doesn't work with that high of a port number. I have removed all
hardware and re-booted, but when re-installed the modem is still Comm 14.

Is there a way to reset the port number to like 3 or 4?

Thanks for Help
Tom Salicos
3 answers Last reply
More about high serial port numbers
  1. Archived from groups: microsoft.public.windowsxp.hardware (More info?)

    Tom S. Lee said in news:unsIyFOPEHA.2256@TK2MSFTNGP10.phx.gbl:
    > I frequently install and remove modems and multi-port I/O cards in my
    > XP Pro system. The Comm port numbers grow, and now my modem is Comm
    > 14. My software doesn't work with that high of a port number. I
    > have removed all hardware and re-booted, but when re-installed the
    > modem is still Comm 14.
    >
    > Is there a way to reset the port number to like 3 or 4?
    >
    > Thanks for Help
    > Tom Salicos

    My guess is that you either still have the enumeration for that device
    in the registry, that you still have the .inf file around for the
    removed modem, or both. I know that I have run into problems with PCI
    modems whose uninstall does not remove the enumeration listed in the
    registry so a subsequent install gets screwed up. For example, the
    enumeration in my current system for my PCI modem is under:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\PCI\VEN_14F1&DEV_10B4&S
    UBSYS_9300141D&REV_89\4&3b1d9ab8&0&4840

    Under there is a value name of "ClassGUID" (global <something>
    identifier). I then did a search on the classGUID and found it under:

    HKEY_LOCAL_MACHINE\SYSTEM\ControlSet<xxx>\Control\Class\{4D36E96D-E325-1
    1CE-BFC1-08002BE10318}

    where xxx = null, "001", or "002". Way too many settings under that key
    to bother checking now. The subkey under Enum\PCI and this classGUID
    key would be the ones that I would try deleting ... obviously after
    first exporting them to permit recovery.

    So look under the Enum\PCI key for VEN... subkeys to see which might be
    for old and non-existent modems. I'd also go hunting in the
    \Windows\INF subdirectory for any modem-specific .inf files to move them
    out so on startup Windows won't reuse it (if you are reinstalling the
    same or similar modem and want to enforce Windows to ask for new
    drivers/definitions instead of trying to reuse the ones already there).
    Sometimes the .inf file defines several modems but if it is a
    vendor-supplied INF file then you can delete it (by moving it elsewhere)
    after removing the modem since an install of modem even by the same
    vendor should install the INF file. However, some modems are so generic
    that they use the INF file(s) provided by Windows which can cover more
    than one brand and model, so don't delete that INF file. You could
    always ask the modem maker if they provided their own INF file so you
    know which one to delete.

    I haven't had to do this for over a year so this is from memory. As
    always, when monkeying around with the registry then make a backup of it
    or, at least, the keys you will edit or delete.

    Description of the Information in the Subkeys Under the
    HKEY_LOCAL_MACHINE Branch of the Registry
    http://support.microsoft.com/?kbid=250405

    An Inf Error Occurs During Installation of a Network Adapter on a
    Windows 2000-Based Computer
    http://support.microsoft.com/?kbid=306983

    According to this last article, you delete the subkey and not the VEN
    key. Don't know why you would need the VEN key since that is supposed
    to identify the vendor of the device and obviously the registry isn't
    going to have a VEN key for every vendor that existed, exists, or will
    exist. But then this article is geared towards a repair rather than to
    eradicate irrelevant definitions.

    However, the above discussion regards the eradication of defunct PCI
    device definitions. It is entirely possible that the ports are defined
    separately (and then bound to these devices). For example, my PCI modem
    got assigned to COM3 (doesn't physically exist so this is a logical
    definition) and I found it under:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\COM3

    But I also found all the ports under Windows defined at:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Ports

    The binding of COM3 to my modem was found at:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceClasses\{adb44
    c00-1b8d-11d4-8d5e-00a0c90d1c42}\##?#PCI#VEN_14F1&DEV_10B4&SUBSYS_930014
    1D&REV_89#4&3b1d9ab8&0&4840#{adb44c00-1b8d-11d4-8d5e-00a0c90d1c42}\#COM3

    where the ...VEN... key has the same name as the VEN key back under the
    Enum\PCI key.

    Lost yet?

    --
    ____________________________________________________________
    *** Post replies to newsgroup. Share with others.
    *** Email: domain = ".com" and append "=NEWS=" to Subject.
    ____________________________________________________________
  2. Archived from groups: microsoft.public.windowsxp.hardware (More info?)

    Hello,
    You should just be able to change the com port number in Device Manager.
    Locate the com port go to properties,
    Choose port settings
    Advanced Tab.
    There should be a box to set the com port.
    Thanks,
    Darrell Gorter[MSFT]

    This posting is provided "AS IS" with no warranties, and confers no rights
    --------------------
    >NNTP-Posting-Date: Tue, 18 May 2004 16:39:37 -0500
    >Reply-To: "*Vanguard*" <lh_811news@yahoo.invalid>
    >From: "*Vanguard*" <no-email@reply-to-newsgroup.invalid>
    >Newsgroups: microsoft.public.windowsxp.hardware
    >References: <unsIyFOPEHA.2256@TK2MSFTNGP10.phx.gbl>
    >Subject: Re: Way High Serial Port Numbers
    >Date: Tue, 18 May 2004 16:39:36 -0500
    >X-Priority: 3
    >X-MSMail-Priority: Normal
    >X-Newsreader: Microsoft Outlook Express 6.00.2800.1409
    >X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409
    >Message-ID: <fpydnbZ8k5YEHzfdRVn-tw@comcast.com>
    >Lines: 97
    >NNTP-Posting-Host: 66.41.115.111
    >X-Trace:
    sv3-FfV0sFhQA+3hB/0xZ+FJLYJJoBIljYZkuhOl08IZs4DLj8eu4wNotueoJNU3XzmAE/+MpziL
    UIjF3dL!gcFuF7DI7XtFyTNLjzvXeMta7IBe+O4AwriGHB0wFKCN9qsTRClGahyQc7dqrg==
    >X-Complaints-To: abuse@comcast.net
    >X-DMCA-Complaints-To: dmca@comcast.net
    >X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
    >X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your
    complaint properly
    >X-Postfilter: 1.1
    >Path:
    cpmsftngxa10.phx.gbl!TK2MSFTFEED01.phx.gbl!TK2MSFTNGP08.phx.gbl!newsfeed00.s
    ul.t-online.de!t-online.de!border2.nntp.dca.giganews.com!border1.nntp.dca.gi
    ganews.com!nntp.giganews.com!local1.nntp.dca.giganews.com!nntp.comcast.com!n
    ews.comcast.com.POSTED!not-for-mail
    >Xref: cpmsftngxa10.phx.gbl microsoft.public.windowsxp.hardware:206093
    >X-Tomcat-NG: microsoft.public.windowsxp.hardware
    >
    >Tom S. Lee said in news:unsIyFOPEHA.2256@TK2MSFTNGP10.phx.gbl:
    >> I frequently install and remove modems and multi-port I/O cards in my
    >> XP Pro system. The Comm port numbers grow, and now my modem is Comm
    >> 14. My software doesn't work with that high of a port number. I
    >> have removed all hardware and re-booted, but when re-installed the
    >> modem is still Comm 14.
    >>
    >> Is there a way to reset the port number to like 3 or 4?
    >>
    >> Thanks for Help
    >> Tom Salicos
    >
    >My guess is that you either still have the enumeration for that device
    >in the registry, that you still have the .inf file around for the
    >removed modem, or both. I know that I have run into problems with PCI
    >modems whose uninstall does not remove the enumeration listed in the
    >registry so a subsequent install gets screwed up. For example, the
    >enumeration in my current system for my PCI modem is under:
    >
    >HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\PCI\VEN_14F1&DEV_10B4&S
    >UBSYS_9300141D&REV_89\4&3b1d9ab8&0&4840
    >
    >Under there is a value name of "ClassGUID" (global <something>
    >identifier). I then did a search on the classGUID and found it under:
    >
    >HKEY_LOCAL_MACHINE\SYSTEM\ControlSet<xxx>\Control\Class\{4D36E96D-E325-1
    >1CE-BFC1-08002BE10318}
    >
    >where xxx = null, "001", or "002". Way too many settings under that key
    >to bother checking now. The subkey under Enum\PCI and this classGUID
    >key would be the ones that I would try deleting ... obviously after
    >first exporting them to permit recovery.
    >
    >So look under the Enum\PCI key for VEN... subkeys to see which might be
    >for old and non-existent modems. I'd also go hunting in the
    >\Windows\INF subdirectory for any modem-specific .inf files to move them
    >out so on startup Windows won't reuse it (if you are reinstalling the
    >same or similar modem and want to enforce Windows to ask for new
    >drivers/definitions instead of trying to reuse the ones already there).
    >Sometimes the .inf file defines several modems but if it is a
    >vendor-supplied INF file then you can delete it (by moving it elsewhere)
    >after removing the modem since an install of modem even by the same
    >vendor should install the INF file. However, some modems are so generic
    >that they use the INF file(s) provided by Windows which can cover more
    >than one brand and model, so don't delete that INF file. You could
    >always ask the modem maker if they provided their own INF file so you
    >know which one to delete.
    >
    >I haven't had to do this for over a year so this is from memory. As
    >always, when monkeying around with the registry then make a backup of it
    >or, at least, the keys you will edit or delete.
    >
    >Description of the Information in the Subkeys Under the
    >HKEY_LOCAL_MACHINE Branch of the Registry
    >http://support.microsoft.com/?kbid=250405
    >
    >An Inf Error Occurs During Installation of a Network Adapter on a
    >Windows 2000-Based Computer
    >http://support.microsoft.com/?kbid=306983
    >
    >According to this last article, you delete the subkey and not the VEN
    >key. Don't know why you would need the VEN key since that is supposed
    >to identify the vendor of the device and obviously the registry isn't
    >going to have a VEN key for every vendor that existed, exists, or will
    >exist. But then this article is geared towards a repair rather than to
    >eradicate irrelevant definitions.
    >
    >However, the above discussion regards the eradication of defunct PCI
    >device definitions. It is entirely possible that the ports are defined
    >separately (and then bound to these devices). For example, my PCI modem
    >got assigned to COM3 (doesn't physically exist so this is a logical
    >definition) and I found it under:
    >
    >HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\COM3
    >
    >But I also found all the ports under Windows defined at:
    >
    >HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Ports
    >
    >The binding of COM3 to my modem was found at:
    >
    >HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceClasses\{adb44
    >c00-1b8d-11d4-8d5e-00a0c90d1c42}\##?#PCI#VEN_14F1&DEV_10B4&SUBSYS_930014
    >1D&REV_89#4&3b1d9ab8&0&4840#{adb44c00-1b8d-11d4-8d5e-00a0c90d1c42}\#COM3
    >
    >where the ...VEN... key has the same name as the VEN key back under the
    >Enum\PCI key.
    >
    >Lost yet?
    >
    >--
    >____________________________________________________________
    >*** Post replies to newsgroup. Share with others.
    >*** Email: domain = ".com" and append "=NEWS=" to Subject.
    >____________________________________________________________
    >
    >
    >
  3. Archived from groups: microsoft.public.windowsxp.hardware (More info?)

    A quick fix (if it works) is to boot into safe mode and
    go to the device manager. There are often remnants of
    previously installed devices that you can see in safe
    mode that don't appear in regular mode. Just uninstall
    those remnants, reboot, and see what happens.

    Mike
    >-----Original Message-----
    >I frequently install and remove modems and multi-port
    I/O cards in my XP Pro
    >system. The Comm port numbers grow, and now my modem is
    Comm 14. My
    >software doesn't work with that high of a port number.
    I have removed all
    >hardware and re-booted, but when re-installed the modem
    is still Comm 14.
    >
    >Is there a way to reset the port number to like 3 or 4?
    >
    >Thanks for Help
    >Tom Salicos
    >
    >
    >.
    >
Ask a new question

Read More

Hardware Modem Windows XP