Laptop switching off after windows xp sp3

[GTS]

Hi There,

I have Asus Laptop A6000U AMD mobile Sempron+3100 1000 mbram that come with Windows XP Home edition.
Laptop always works fine however during the process of download of the SP3 the laptop has died. It has been switching off every 2-10mim. I tried everything and at the end I have completed formatted the Hard disk, Laptop was still switching off. I them bought and have installed a new hard disk (recognised and installed fine at bios) and Laptop still switching off after few minutes. I can not even start to install windows XP again because the laptop will switch off after 2 mim. Has Microsoft SP3 destroyed my hardware? How come? Is this possible? Any one there any idea? I looked at the bios and I don’t see any setting that I can be related to that, but I am not an expert. I choose to select load for optimal setting witch I think is the standard manufacture settings and that how it is at the moment.
Please I would really appreciate any comments.
Many Thanks