Several of the new Windows 2000 laptops on the market do not have serial ports. If you install one of Digi's network devices off of the NIC, using a crossover cable, to give you serial ports, the Digi driver fails to load with Code 19.
This behavior occurs because the virtual COM port the RealPort driver is trying to configure relies on the standard serial port driver (Serial.sys) that is included with Windows 2000. This driver, however, can start only if there is at least one hardware serial port that requires the driver.
To load the Serial.sys driver go to Add/Remove Hardware Wizard on your Windows 2000 laptop and try to manually add a com port. This com port will not be used with the Digi, but used only to load the Serial.sys. If the com port successfully loads, the RealPort driver should finish loading correctly and the com ports should appear in Device Manger under Ports, with no error message.