Vostro 1500 freeze

First of all I would like to say how dissapointed I am with DELL. The problem I am going to describe occured from day1 and still one year later it is still there. My warranty is past due now and the numerous calls and money i spent with dell support were in vain. All the advice i got form the people on the other side of the phone were reinstall your OS and they didnt even bother to send any1 to check my notebook. So i decided to give it a try a check these forums for answers.

My laptop is freezing whenever it wants to. I can hear the scratching noise from the hard disk when its opertating but at some point the disk stops and the computer freezes. I have used windows vista buisiness 32 bit only. My tech specifications are:

System memmory 2gb

Intel Core 2 duo CPU T5470 @1.6 GHz

Graphics Nvidia Geforce 8600M GT 1023 total availible graphics memmory

I have re installed windows countles times hoping that those freezes will stop but nothing has happened so far. I have run all the tests there are including those initiated just after start up. None of them say that any piece of hardware is working incorrectly. The current drivers i use are only the video drivers. I noticed that every time I install the chipset dirvers or the hard disk ones or any other the computer laggs even more and freezes a lot more. If i am browsing the internet  or watching something on my laptop freezes are not that common however when I start gaming its . I play only world of warcraft form time to time and whenever I log in my hardisk starts "scratching" like mad and 30 seconds later it stops and guess what....... a freeze and after a while its running again. And this can happen either every now and then (about every 15-30 mins) or in intervals of less than a minute. Apparently the people at the customer service centre dont believe or cant be bothered to help besides making me run all the tests they have memmorized and tell me to reinstall windows. I wonder if anyone of you has encountered this particular problem and has found solution for it. It is simply unbearable I cant use this computer for anything but browsing the internet. I cant even use with its battery because if I put it on low power mode it takes about 20 to 30 minutes to start up while freezing and unfreezing. So basically I feel like I have wasted my money on a machine that can only browse the internet and cant do anything else because if I load the system even the slightest bit it starts blocking. In my oppinion someone messed up big time when putting together my laptop.

Please any help would be highly appreciated.

Edit: I tried to remove vista and install XP sp3 but when i booted from cd rom to proceed with install the machine said hard disk not detected. I presume there is somekind of tweak that Dell makes so laptops are specified to one type of OS only. I am wiriting this because I remember reading somwhere that Vista is too heavy for 1.6GHz dual core processor and downgrading to XP might do the trick. I am desperate so would try anything.