If I understand this correctly this computer is only six months old, I don't quite understand why you re-installed windows and re-partitioned the hard disc! Is the machine not under warranty? I would suggest a lot of the problems stem from a faulty hard drive, either the drive or the drive actuator.
If your machine is reporting hard disc errors why didn't you get Evesham involved? What do they have to say about all these problems? Surely it's in your best interest to let them know what's happened with your machine,isn't it?
You have my sympathy of course, but it does seem to me that the one advantage in buying a computer from an firm like Evesham, is the advantage of having a warranty to repair the machine if it is necessary.