COM3 Incorrectly Reported as Local Port by Windows

ID: Q83422

The information in this article applies to:

Microsoft Windows versions 3.1, 3.11

SUMMARY

When you choose Connect from the Printers option in Control Panel, COM3 is detected as a local port even when there is not a physical COM3 port present.

MORE INFORMATION

Choosing the Connect button displays the list of available ports with a description of the ports' usage. The descriptions will be one of the following:

Network Connection: This displays the current network printer connection for that port.

Local Port: This option is reported if Windows detects that the physical port exists.

Local Port Not Present: This option is reported if Windows does not detect the port or if the port is currently being used by another device such as a mouse or modem.

For COM3, Windows will use the default address of 3E8H for COM3 even though the port is not physically present. Because this default address is used, the port is always recognized as a local port.

For more information, query on the following words in the Microsoft Knowledge Base:

win31 COM serial ports 3.1

Additional query words: 3.10 COM2

Keywords :
Version : WINDOWS:3.1,3.11
Platform : WINDOWS
Issue type :