When you install a multi-port serial adapter on your Windows 2000 computer, the COM ports (COM3, COM4, etc..) are registered in a COM port database.

If the adapter is removed, or does not work, and you install a new multi-port serial adapter, it may not resuse these COM ports, and assign higher COM port numbers.

The proper way to install a new multi-port serial adapter, is to remove the old adapter, using the Add/Remove Hardware tool or Device Manger, while the old adapter is still functioning.

If you can't, use the following method, before you install a new adapter:

1. Control Panel / Add/Remove Hardware / Next / Uninstall/Unplug a device / Uninstall a device / Next.

2. Select the Show hidden devices checkbox.

3. Select the multi-port serial adapter and press Next.

4. Press Yes, I want to uninstall this device and press Next and Finish.

5. For each COM port:

    Control Panel / Add/Remove Hardware / Next / Uninstall/Unplug a device / Uninstall a device / Next.

    Select the Show hidden devices checkbox.

    Select the COM port that you wish to remove and press Next.

    Press Yes, I want to uninstall this device and press Next and Finish.