External/Portable HardDrives

I have a HP Win 7 64 Laptop. I am planning to get a external/portable harddrive.

Plzz suggest good ones.

I plan to get 1TB.

Currently I am getting it to store movies & personal stuffs i.e my data drive where I store all personal stuffs like photos, documents, movies, etc. May be I will backup system drive & store system image.

Are the preinstalled autobackup & other softwares necessary or external harddrives can be used like flash disk i.e attach to the laptop & copy-paste whatever you want to?

Can external harddrive be formatted so that all the preinstalled softwares are wiped?

Are external harddrives for laptops different than external harddrives for desktops?

My laptop has USB 2 & Esata, no USB 3.

Suggestions & info plzz.