Answer:
For a Windows system, uninstall and reinstall the software. This will restore the default settings, and will not harm the array.

For Mac OSX, open a terminal and delete the following file:

hptuser.dat 

This file is located in: /etc/

The software will rebuild the file after a reboot, and restore the default login settings. This will not harm the array.

Default settings:

Username: RAID
Password: hpt