Pc shutting down randomly

my pc is just 9 months old here are the specs http://screencast.com/t/SqjTHmqv at random times it is shutting off on me for instance this morning it shut down with in being on for 10 mins but yesterday stayed on the entire day and half the nite no problems...i shut down completely when i go to bed so it is NOT left on overnight ever....this morning it was not warm or even hot usually it is like luke warm in the bad but never hot or anything i checked the fans they are all runnin fine and dusted all vents off...so whats my next step that i may need to do? idk if i have a virus or whats going on just in the past month maybe less at odd times its been shutting down...also i can reformat either there is another post about that with a screen shot...says i need media disk because some media files are missing....this is the strangest 2 things i have even seen before and i have been working on pcs since i was 15...any help tips or suggestions are welcome...i also have skype as well that will be easier than discussing via text...if u wish to use skype leave your addy and i will add you..TY very much in advance for all help and info...hopefully we can get this problem rectified ASAP!

 

what OS is your PC running?

 

it is windows 8 now when i try to reinstall windows 8 it shuts down when it is supposed to be restarting so i am not sure if there is yet another issue that should be addressed as well i have been working on this since yesterday and still no PC...is there anything i can maybe change in the system that will make it restart after installing windows instead of shutting down...i have no OS atm because it doesnt install all the way obviously because of the shutting down issue...it is NOT hot at all i just find it strange that when it is supposed to be restarting it shuts down so something needs to be changed...get bk to me ASAP if ya can ty!)

 

try turning auto-shut down off in the bios that could help,
also check the internal hardware is properly secured, lose hardware can cause problems and incorrectly placed hardware as well.