Download the latest nVidia drivers for your card. Uninstall your current drivers, reboot, then install the newer drivers. That will tell you if it is a driver issue related to the card or enabling 3D.
If you still have a problem, then download a free application like Speedfan, and check the temperature of his CPU and GPU. If the temps are 35-55 C depending on load, then you are not overheating. But if Speedfan temps for the video card or motherboard report something way too high, try another free temperature monitor before you panic.
But if your temps are cool, heat is not your problem. If your temps are high, then make sure you clean the fan on the CPU and video card, and even your power supply if it feels too warm.
If heat is not your problem, have you done any recent upgrades or installed any other drivers or software recently? If you have recently installed the RAM, it is possible it has errors and you should use something like memtest86+ to find out. If you haven't touched the hardware recently and it has been stable, then your memory is probably fine.
Some software or unstable drivers can cause your computer to act up. So make sure you install all the latest drivers and run a complete virus scan.
After checking all the above, if you still have this issue... report back to us. It is possible the PSU is becoming weak.
BTW, what is the exact model of the PSU? If it is not a good brand and you've had it for a while, it is possible it's going out on you. And which OS are you running?
Dust can make the temperature too hot and force the computer to restart. You didn't answer my question yet. What are your CPU and GPU temperatures? Did you download Speedfan and check? I can't help you a lot until I know what are your temperatures.
And also I asked, did you recently install any new drivers or software? Or have you recently run a full virus scan? If the probably suddenly happens for no reason, it could also be a software or driver conflict.
But first, I need to know what is your CPU and GPU temperature.
The GPU temp you showed is normal. But the CPU should be between 30-70. But over 50 when not under a load is way too hot. Open up the side of your case when you turn on the PC and make sure all the fans are working normally and not stuck or full of dust.
Sometimes Speedfan doesn't tell you what Temp1 and 2 are, but I am assuming it is your CPU over heating. Try to find the H/W Monitor in the BIOS to confirm what Speedfan is showing you.
Now would also be a good time to take the side panel off the PC and check to make sure the CPU fan is running when the computer is powered on. If it's not moving or it's full of dust, now would be the time to start cleaning it out. Or if the fan isn't moving at all, now is the time to replace the stock cooler.
If that heatsink/fan is VERY dirty, I suggest you purchase some more thermal paste, so you can remove the heatsink and clean it. If you removed it, you should use some alcohol and a coffee filter (or anything that doesn't leave fibers behind) to clean the CPU surface and the surface of the heatsink that touches the CPU.
While the heatsink and fan is removed, use an old tooth brush, take it outside... and you can probably figure out how to clean the blades and fins.
Then re-apply thermal paste, remount, plug the fan connector back in and then boot up and check results.
But if your heatsink fan isn't clogged and you are getting such high temps, make sure one of the clips from the CPU heatsink didn't come disengaged. That would make the heatsink not sit flush and allow direct air between the CPU and heatsink. So that would cause a quick overheating issue also. Just make sure all the clips are secure and there aren't any gaps around the CPU.
Ok. I can understand what you are telling but the problem is that why is it heating that much when you turn it on after letting it to cool for about 5 hours. I got this temp result after about 20 minutes counting from the starting of the computer
Not really but they underclock themself when not being fully utilized (like Intel Speedstep). And if the heatsink is too clogged, the fan isn't working properly, or one of the clips came off of the CPU cooler mounting... then your temps will build up on you.
Even if the fan is off, you can still use the CPU for a few minutes with no heavy load and it'll run. But after it gets over 70C it will become unstable. And over 100 is just plain dangerous and of course between 70-100+ it will crash.
Did you open the case and look closely to make sure the CPU fan is working properly and not full of dust?
If the CPU fan the stock Intel fan? Does it look like this? If so, make sure the 4 mounting clips are secure and one of them did not come loose from the heatsink. If one of them is loose or broken, the heatsink is not flush and it is not keeping the CPU cool.