XP and external Hard drive upper limit?

I'm considering purchasing a Cavalry 1TB Dual Interface - USB 2.0 & eSATA External Hard Drive - CAXA3701T0.

I'm running XP HE v2002 SP-3.

What is the biggest hard drive XP will recognize?

I'm not really a computer guy. I mainly want this for storing videos, more or less to act like a dvr for my computer...and to use to back stuff up.

By the way, do think that's even a good idea and will it even work? Do you know of a better way to accomplish this?

Need and appreciate your knowledge and opinions!