Symptom:

While installing a Digi AccelePort Adapter on a Microsoft Windows XP-based computer, setup may be halted during the device-detection phase by the following warning message: 
The software you are installing for this hardware:

your specific hardware

Has not passed Windows Logo testing to verify its compatibility with Windows XP.

Cause:

This behavior can occurs because setup is attempting to install or migrate an unsigned device driver. Windows XP warns the user when an unsigned driver is about to be installed and asks for confirmation.

Solution:

To prevent setup from being halted with this warning message: 
Set Driver Signing Policy to Ignore 
This can be found by going to Control Panel, System, Select the Hardware Tab and click on Driver Signing.