Easy but the software is the key.
The Maxtor comes with Retrospect which is OEM limited functionality. The key program - One Touch works from one computer but the interface makes it look like flying a jumbo jet. Fail to understand it and then go to the website for help and you are in danger of being persuaded to spend a fortune on software upgrades.
It depends what you want to back up. Files only i.e. My Docs no problem. But Windows Back up is fine for this. Operating system and you are in a different league. Even when you think you have a rock solid back up when the crunch comes you'll invariably find it bombs on you.
If I had known then what I know now I'd have fitted every computer with a second hard drive. With Windows XP and SP2 it's no more difficult the building Lego!! AND IT IS MILES CHEAPER.