First off, sorry about your father's passing. That's always a painful event.
I've had the LaCie Firewire 400 120GB drive attached to my PC for several years with no problems. At the time it was purchased, there weren't many cost effective alternatives for external HD's.
I'm always amazed at advice on web sites. You probably have a perfectly good drive, but "memory is cheap", so just lay out another $120 for a different HD. I don't get it. IMO 120 GB will hold a lot of images, more than enough for the average amateur. Periodically, you'd probably want to dump off some of those files to CD's or DVD's anyway, as an alternative backup strategy.
Please do not be put off by some of the comments regarding LaCie's reliability. I've seen plenty of posts on various sites regarding crashes of WD & Seagates also. That's just in the nature of HD's. The one valid point is that when you buy one of those, you know whats in the box. For me, that hasn't made a difference with this unit.
Regarding your original question, assuming yours is the firewire version, the top round socket is for the power brick and below that two firewire slots. One connects to the computer and the second allows you to connect a second firewire drive in a chain. The only identification besides serial number mine has is a sticker with "T 5148 LL/A" on it. Don't know if that's the model number or not.
No software is necessary as all you need do is connect it to your computer, power it up and Windows should recognize it. You would then access it through "My Computer", where it should show up as another hard drive.
Perhaps if you need more information, you can look at LaCie's web site www.lacie.com
. They may not list your particular model anymore, but use the "Contact Us" area and you should get some help.
Good luck,