Make sure that the system has at least one of it''''''''s native serial ports enabled in the system BIOS. Failure to do this will prevent the Microsoft Serial Driver from loading. The Digi makes use of it and will not be able to load without it, hence the missing com ports.
If the native serial port (usually Com 1)is having trouble loading then try changing the IRQ and/or the memory address. It is possible that there is a conflict with another device.
If using a laptop with a docking station, make sure it is firmly connected. A bad connection could prevent the com port from loading in windows 2000.
If using a desktop, the problem could be caused by a bad connection. Try powering the system off, reseat the digi card, and reboot.
If the problem persists try changing, if possible, the assigned IRQ in the system BIOS. This may not be possible if the BIOS doesn''''''''t support it however.