I'm going to buy a 1TB portable drive to copy things onto a notebook computer which I have as a back up/alternative. Both machines are Windows 7.
I see two with good reviews that seem a very similar decent price (approx £55 & £52), and wonder if either one is better than the other:
Samsung 1TB M3 Portable USB 3.0 Hard Drive Black (3yr warranty)
HGST 1TB Touro Mobile MX3 USB 3.0 Portable Hard Drive (2yr warranty)