Err Msg: Ring 0 Systems. Virtual 16550 Driver... (117668)


The information in this article applies to:

  • Microsoft Windows for Workgroups 3.1
  • Microsoft Windows for Workgroups 3.11
  • Microsoft Windows 3.1
  • Microsoft Windows 3.11
  • Microsoft Windows 95
This article was previously published under Q117668

SYMPTOMS

You receive the following error message when you start Windows:
Ring 0 Systems. Virtual 16550 Driver Board was not found in computer. Virtual 16550 & communication buffering in the DOS box will not work. It may cause lost bytes during the data transfer and other problems with communication software running under V86 DOS

CAUSE

This error occurs when you:

  • Move your modem to another serial port without reconfiguring the driver.

    -or-
  • Remove the modem from the computer but do not remove the corresponding Digicom Systems Incorporated (DSI) device driver (r0dsicom.drv). This device driver replaces COMM.DRV as the Windows serial communications driver and displays the error message noted above when it doesn't find the modem.
The following modems use DSI-written device drivers:

  • Boca Sound Expression 14.4 VSP
  • Cardinal Technologies MVP144DSP
  • DSI Connection Series
  • PC Logic FAX144DM

WORKAROUND

  • If you move the modem to another serial port, run the DSI.EXE program included with the modem to reconfigure the adapter. Contact DSI for more information and assistance.
  • If the modem has been removed, the DSI drivers should be replaced with the default Windows drivers to remove the error message.

    The DSI setup program makes the following changes in the [boot] section of the SYSTEM.INI file: 
         COMM.DRV=r0dsicom.drv
    To replace this DSI driver, change this line to read as follows: 
         COMM.DRV=COMM.DRV
    The following changes are made to the [386Enh] section of the SYSTEM.INI file by the DSI setup program: 
          DEVICE= r0dsivcd.386
      DEVICE= r0dsibuf.386
      DEVICE= r0dsimgr.386
    Remark out or remove the above three lines and add the following to the [386Enh] section: 
          DEVICE=*VCD
      DEVICE=*combuff
    NOTE: The Connection Series modems require the drivers outlined above for full functionality. You should not replace the DSI drivers listed above unless the DSI modem is removed from the system. Contact DSI for more information.

MORE INFORMATION

The products included here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.
Modification Type:MajorLast Reviewed:2/8/2002
Keywords:KB117668
©2002 Microsoft Corporation. All rights reserved.