Remove your Video card and RAM sticks, clean them with a dry cloth and then place them back,also chek for any cloged vents your having,also if your MB is ASUS try letting the pc on for 1-2 hours then Manualy check the temp of your heat sink (put 2 fingers on the CPU radiator) and if its hot post here for a resolve
EDIT:
-That tearing your having and the PC restarting is a sign of Hardware failure,also the fact you moved to the integrated GPU is a bad sign,either your Dedicated GPU is dying or the temp is high as hell (summer games).Also check your PSU conectors for burned whires,mabe your PSU(power suply unit) is near its death.
-Had similar problems and it turned out i had a dead fan on my Video Card and 3 burned conectors on my PSU's power cuplings
-NEVER GIVE HIGHER SETTINGS TO YOUR TEPM RESTARTING OPTION
-AND NEVER TEMPER WITH BIOS SETTING IF YOU DONT KNOW WHAT YOU ARE DOIING