For your immediate issue, using the Offline NT password recovery disk, please run the driver autoload several times. You're on a G5 ProLiant, and the utility needs to run the probe separately for each SCSI device driver. (e.g. you may have an Adaptec or LSI device that was probed first). There was a bug in the program that wasn't resolved until the 5/2011 release.
If that fails, you have a number of password recovery options available. HP equipment is pretty standard and its CCISS block device drivers are available in most rescue CD solutions.
My approach is to use the PLD Rescue CD for this purpose. It's ~80 Megabytes and includes the
chntpw NT SAM password recovery utility. I'm sure this could be substituted for any other modern Linux-based rescue disk, but this is part of my toolkit.