External Hard Drive question

[Mauxe]

I read through some posts where people mentioned that they played the game from an external HDD and I am wondering about the specifics regarding that.

I am taking a trip for work next week and would like to play the game a bit at night from my work laptop. Would I need to install anything on the laptop itself or can I have everything copied over to the external and launch/play from there?

Thanks for any help!