"Unable to Create Symbolic Link" Error Message When Installing a Modem on a COM Port (254019)


The information in this article applies to:

  • Microsoft Windows NT Server 4.0
  • Microsoft Windows NT Workstation 4.0
This article was previously published under Q254019

SYMPTOMS

After you install a modem on a COM port, you may receive the following error message in Event Viewer:
Unable to create symbolic link for COMx
This problem can occur with any COM port listing.

CAUSE

This behavior can occur if you are using an incorrect I/O address or IRQ.

RESOLUTION

To resolve this issue, use the appropriate method.

Method 1: Remove the COM Port and Let Windows NT Redetect the Port

  1. Start the Ports tool in Control Panel.
  2. Click the COM port listing, and then click Delete.
  3. Click OK, and then click Close.
  4. Restart Windows NT.

Method 2: Change the I/O Address or IRQ of the COM Port

  1. Start the Ports tool in Control Panel.
  2. Click the COM port listed in the error message.
  3. Click Setting.
  4. In the Inside Setting for COMx section, click Advanced.
  5. Change the BASE I/O Port Address to a location that you are not using.
NOTE: You can refer to Windows NT diagnostics to find out which I/O port addresses are in use. By default, COM1 uses 03F8-03FE, and COM2 uses 02F8-02FE.

Method 3: Change the IRQ

  1. Start the Ports tool in Control Panel.
  2. Click the COM port listed in the error message.
  3. Click Setting.
  4. In the Inside Setting for COMx section, click Advanced.
  5. Change the COM port to an IRQ that you are not using.
NOTE: You can refer to Windows NT diagnostics to find out which I/O port addresses are in use. By default, COM1 uses IRQ 4, and COM2 uses IRQ 3.
Modification Type:MajorLast Reviewed:8/6/2002
Keywords:kberrmsg kbprb KB254019
©2002 Microsoft Corporation. All rights reserved.