PC switching itself off

apple

Hi all, i have a problem with a friends PC. It started of with the sound not coming through the speakers when playing a cd rom or playing at all a DvD. just before the window music comes on before the desk top comes up you can here that. I know the speakers work and i use a second pair.

the PC was very slow so i defraged it and ran a anti spyware on it. Which speeded it up a lot. the picture run more smoothly but still no sound. Now i am thinking the i need to up date the drivers on the PC. So i have brought it over to me home as i have the internet. With in an hour of doing this the computer has now started to switch off and the length of time that i have from starting up to the PC shutting down is getting shorter and shorter. Could it be on its way out?

Thanks any help                    
      

check the temps to see if this is causing the shut down

download this  from : localhost/ its a motherboard monitor

if it is the temps the you need to open the pc and give it a good clean to remove all the dust
.
the sound when playing a dvd may be a codec problem ..

download this codec pack

from : localhost/finalbuilds.edskes.net/klcodec.htm 7.18MB standard

or download this player  from : localhost/