Computer shut downs

Hi guys,

ive had a problem with my current computer for agggess somtimes it will just randomly shut down but just like ive pulled the cable out and then i have to turn it off and on at the wall to make it work again! Also somtimes during start-up i get a dark blue screen which triggers my computer to restart and then it goes in a loop.

i wondered if you guy have had the same problems and/or know how to help me.

thanks!