Virtual PC cannot support more then 16 USB devices. Disconnect one or more USB devices and try again.

    General discussion

  • Inside of Windows XP mode - Windows Virtual PC, When I click on the USB button (to attach/detach USB devices), a popup appears, titled: "Windows XP mode - Windows Virtual PC" with a big red X to the left of the message: "Virtual PC cannot support more then 16 USB devices.  Disconnect one or more USB devices and try again."

    I poked around but haven't found a cause, solution or any mention of this exact error message on the Internet yet.
    I do not have 16 USB devices appearing anyplace (device manager, etc).  I can't attach any because I can't get past that message, Clicking OK dismisses the pop-up until clicking on the USB button again. 

    I do show a yellow question mark in device manager next to Virtual PC Integration Device, and have not been able to install drivers for what ever that is, not sure if it's related to the error message in question, and inability to add a USB device.

    Any explainations or solutions for this?
    Advance Thanks, and Happy Thanksgiving.

    Thursday, November 26, 2009 5:55 PM

All replies

  • I have since uninstalled both Windows XP Mode, and the VPC (Windows6.1-KB958559-x64.msu), restarted, reinstalled both, and still same result, except now I have to re-apply all the XP Patches again....

    I wonder what makes it think there are 16 USB devices? 
    -Clueless in Cleveland.
    Thursday, November 26, 2009 7:50 PM
  • I am having the exact same problem now.  I did not have this issue before.  I get that same error pop up window and can't get to the dropdown that would allow me to disconnect a USB device.  This is the first time I've experienced it and have not had the problem in the past.  I really need the XP Virtual Machine now to help troubleshoot an old all in one scanner/printer that doesn't have Win7 drivers and won't install in Win7.  I'm not sure why today this issue has raised its ugly head, but I'm hoping Microsoft will supply a fix for it soon!
    Sunday, February 19, 2012 2:33 AM
  • To Microsoft Tech Support:

    Is there an enumeration issue in the XP Virtual Machine registry?  I looked through the registry to find if I could see a USB attached counter that was greater than 16 or more than 16 USB devices identified as being attached.  I could only find a few that were currently attached and one or two that had been recently attached but removed.

    Not sure if this has any effect on the VM issue, but I've noticed several times when a USB external hard drive is attached and I try to eject it, it says the drive is in use and I need to close out the program using it before it can be ejected.  However, there are no programs open or accessing the drive, so the only option is to yank the drive without ejecting it first.  Usually when I've had to do this, I do not have the VM running, but not sure if Win7 is passing bad USB connection data through to the VM XP operating sytem.

    Also, since TheNetDr's post never went answered by MS tech support, I doubt highly that mine will either.

    I really need a fix for this as my only XP notebook had a hard drive crash recently and I can't get it up and running to check out this legacy printer for a friend.  This is getting totally frustrating to say the very least.

    Does anyone know if MS is going to see this post, or was typing all of this information just a waste of time?


    Sunday, February 19, 2012 7:18 PM
  • Probably the reason there is no answer from Microsoft Tech Support is because this forum is not a Microsoft Tech Support forum.

    This is a peer-to-peer user forum for exchange between Windows Virtual PC & XP Mode users.

    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”

    Sunday, February 19, 2012 7:41 PM
  • Thanks Rick.

    No sense spinning my wheels around here anymore.  I doubt anyone will post with a viable solution here.

    Sunday, February 19, 2012 7:51 PM