In our case this error occurs because of a special license key fob attached to the serial port. The error is correct, it is not a serial port. This particular fob is for Avaya Voicemail Pro.
From a newsgroup post: An error message appears in Event Viewer if you attempt to configure a com port that physically does not exist on the system. Suppose you went to the Ports option in Control Panel and added a COM3 port, when in fact you physically only have COM1 and COM2 on the system.
The event log message id 11 means that the system will delete the I/O address entry for the non-existent port in the Windows NT internal I/O port address table. The entry for this non-existent port will still exist in the Ports option of Control Panel and in the appropriate key of the Registry.
To clear these messages from Event Viewer, do one of the following:
- Use the Advanced Settings dialog box to change the I/O, IRQ, or the COM Port Number setting
- Delete the appropriate entry from the Windows NT Registry using Registry Editor.
Using the Advanced Settings dialog box clears the error messages in many cases, but in two cases you need to delete certain entries in the Registry:
- If you want to change the settings for a COM port already detected at Setup by NTDETECT.
- If the COM port in question doesn't physically exist on the system.
In the first case, the Advanced Settings option will not be available. In the second case, no facility exists in the Ports dialog box to delete the entry for the non-existent COM port. To delete the false entry from the Registry, use the Registry Editor (REGEDT32.EXE) to find the following key:
The Parameters key lists one or more subkeys listed as Serial10000, Serial10001, and so on. Check the DosDevice value to find which subkey represents the non-existent COM port. Then, highlight the subkey for the erroneous serial port and choose Delete from the Edit menu.