Well, it started around one month ago. My computer sometimes wont start, just before starting on the monitor or after it will get shut. After pressing power button 3-4 times it will eventually start and would not show any kind of problem after that. Sometimes it will allow me to see the INTEL logo for awhile and then shut. I just did not have enough time to check the hardwares as I were busy with some family matters. Today I replaced my old SMPS with a new one and it worked flawlessly, rebooted numerous times without any problem. The question is how much rating (the current one is 600W) should I use for my SMPS and is there any way to prevent them from burning out? I changed another one year ago, in the summer. Here's my Specification: M/B: Intel® Desktop Board D101GGC Processor: Pentium D 2.66 GHz Monitor: LG 700B (17" CRT) Speakers: 800W Intex Sub-woofer (I hardly use them, pretty happy with my iBall i342MV Headphone) There are no other external hardwares, Video Card and Graphics is embedded, uses 64 MB from my 768 MB RAM. All hardwares are cleaned and the Thermal Adhesive is fine too. Power supply and the cords are checked. CPU temperature is around 60 deg. Celsius and the fan's RPM is around 1800-2000 normally. While I am not doing any intensive tasks the CPU is less then 2-3%.