PLEASE HELP graphical issue

[Ashtrolite]

BY the time i'm writing this it is mid summer and with that it means its hot and i believe that might be my issue but anyway mid spring i bought a Nvidia GTX 750 PNY graphics card and i was really excited to get have it and i immediatly found improvement but when i run games at high graphics settings especially after the computer has run for 4 hours or more it shuts down and restarts automatically i have searched high and low and found many answers but none work my PSU is really cheap and i cant buy a new one at the moment but im working toward it hoping that will fix but its interupting my gameplay and overall messing with me... i dont know much about computers but as soon as i installed the graphics card and it started restarting i knew something wasnt write


8gb Ram

350 watts PSU

 

[CountMike]

Yes, I would say that PSU is on low side. If it's old and not a good make even much so. Try underclocking card a bit, see if that helps any.