PC World and places like that often sell "no name" laptops.
These are laptops made in the far east and then "badged" by PC world or whatever.
Generally they are cheaply made and do not have a good reliability record. You also have no idea what support is like for these brands.
Last month PC World did their reliability review where they asked people to say how reliable different makes were.
For laptops brands like Toshiba, Lenovo (IBM), HP, Acer, Gateway, Dell, ASUS and Samsung scored highest (5 or 6 stars each)
Bottom was Advent (sold only in PC World - 1 star) and Packard Bell and Medion (2 stars).
Do yourself a favour a buy a good brand like Toshiba, HP or similar.
You may pay a bit extra but it may run for years without a problem, whereas a brand like Advent may need to go back to the shop a couple of times.
I was in Staples just this afternoon and saw a Toshiba for about �350 and that will be a FAR better bet than the E System you saw.