So ive had this computer for about 6 years now, and i have had this problem since i got it and i have not been able to figure it out in 6 years. I have a 650 W PSU, a nvidia GTX 560 ti, AMD Phenom quad core processor, a ASUS motherboard, 5 GB of ram, a 1 tb sata hard drive. When im playing games it will just power down with no warning and the lights in my computer shut off, the monitor shuts off, and the lights on my mouse shut off, but my keyboard lights stay on and they flicker. I know its not overheating, nothing runs over 45C at any time, and there is never anything that always shuts it off. Sometimes it will shut off as soon as the game opens, other times it will be as soon as a map loads, and other times even if i alt tab it will shut off. Ive checked all of my connections and everything is tight, ive dusted everything out, ive tried just about everything, and i have tested everything except the motherboard because im not sure how, and the power supply. Also, sometimes it wont shut off for 10+ hours of straight gaming, then ill get on it and play later and it will constantly shut off when i try to play games, it has gotten worse the longer ive had my computer, and lately after my computer shuts off when i start it sometimes it will give me the BSOD saying Something about less or not equal, and something about a folder in nonfolder area or something like that im not sure. I just dont know what else to do if any of you can help me that would be appreciated, thank you. Also i have used windows xp and windows 7 on this computer and i had the problem with both.