4Gb and an i5 will be fast in most circumstances. If you are gaming then the graphics card is the most important issue and I cannot see the computer you linked us to as they seem to have removed it.
Well I can tell you know nothing about computer really, but that laptop comes with 4gigs and that should be fine. Vista needs a minimum of 2GB, but it was the biggest piece of crap Microsoft ever created and 7 is so much better so you should be fine, but get a mouse because Acer track pads suck.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.