You never know when it is going to happen. My old Dell (2003 vintage) overheated and died. I did use a USB driven fan cooler pad under it most of the time. But upon disection, the little fan was designed to blow the air through a small 'radiator.' This was plugged up with a thick mat of dust! Would be easy enough to clean. Only one screw on the bottom and the fan lifts out. Then you can see the clump of dust.
The new computer is a HP 17" with dual core Turion X2 64. Of course it is also Vista. Have to learn the differences!
This did put me several days behind in processing the wedding pictures from last weekend, but this machine is so much faster, it will be a pleasure working on them.