It's a really sucky PSU, I don't think it even has a brand -*-
Because my dad bought this computer for me a long time ago, I didn't know much about computer back then.
But anyways, the power supply is 450Watt, and I think I have found the problem.
After the computer has shut down itself for about a dozen times, I started monitoring the BIOS screen until it shuts down, and found out that it shuts down whenever the CPU temperature reaches 102 Celsius
Yes, that does sound ridiculous, I overclocked the CPU 30% using the AI Overclocking and the CPU was only at 62 Celsius before it started breaking off, and the CPU fan RPM was at about 4500.
But when I took the CPU fan off to clean it, the RPM dropped down to only 2600RPM and the "NOT-OVERCLOCKED" CPU was at 70 Celsius to begin with, and slowly increased to 102.... and shut down.
I am going to buy some more thermal compound these days, and I'll scrap off the old ones and replace it with the new one, I hope this works. If I doesn't, I am going to try a new CPU Fan.
Thanks for replying, your time and help is very much appreciated =)