In October I will start studying and I would like to purchase a new laptop.
My budget is up to $1000
The size should be 13-14 inches and up to 5 lbs
The screen resolution is not that important, however watching HD movies can be nice but not a priority
It should be portable
Battery life should be something in the region of 5 hours
No need of games
Mainly working with ms office and internet
Hard disk capacity isnt an issue
I would like to work with the laptop for 3-4 years
Tried to give as much information as the FAQ suggested
5 hour battery life with any type of use is very unreliastic, especially with a 5lb weight. If you want to have that much battery life you need a netbook which would take away watching HD or the screen size you want.
You should check out the Acer Aspire Timeline 3810t. It has up to 8 hours of battery life and only weighs 3.5 lbs. It also has a multi-gesture touchpad. The laptop doesn't have an optical drive, but that may not be an important feature for you since it meets most of your other specs.
I'd recommend cutting your budget in half. You can get some great deals nowadays and if your not gaming and want battery life than you can get either a i3 or some form of ULV laptop and have it do everything you want, and do it well. I fix laptops for a living and have decided that $550-$700 is the sweet spot. laptops don't consider their prices before they fail.