My computer turns off and on again for a few seconds. (this time it will bootup) when i pressed the power button. i already change the ram to 1gb but the problem still occurs. What can i do to fix this problem? my harddisk has no badsectors and working properly.

It may be owe to software problem 1, the virus "shock" virus attack will prompt system will automatically start in few seconds. From the remote control you Trojan program all the activities of the computer, including let your computer restarts. Remove viruses, trojans, or reshipment system. 2, the system files damage system files destroyed, as the KERNEL32. Win2K DLL Win98 features, the font list below such basic execution system files destroyed at startup, system will therefore cannot finish initializing and forced the restart. Solution: cover installation or reinstall it. Hardware problem: 1.Chassis power is not enough, dc output is pure, the dynamic response sluggish. Users often ignored or assembling businessman, using cheap price of power supply, so is the largest system of automatic restart suspicion. (1) the power output power shortage, when run large 3D gaming occupy CPU resource of software, the CPU needs power supply, power is not caused by overload protection, stop the power output. After the output power to stop, load, reduce power restart. Due to the protection of the recovery/time is short, so we are hosting automatic restart. (2) power dc output is pure, pure dc power supply of digital circuit requirements, when the power output of too direct, the harmonic content will result in digital circuits, performance is often work to crash or restart. (3) working load of the CPU is dynamic, on the current requirement is dynamic, and the dynamic response speed quickly. Request Some of the poor quality power dynamic response for a long time, could also lead to crash or frequent restart. (4) high-end graphics update equipment (large disk/video card/equipment (increased), after the hard disk) / burners, power supply of original beyond rated output power will cause the regular crash or restart. Solution: now in high quality high-power computer power. 2.The memory chip thermal stability, incorrect or damage to restart the system memory problems to restart the system of risk. (1) the poor thermal stability of memory, boot can work normally, when the memory to a certain temperature, temperature is can not work normally, which leads to crash or restart. (2) memory chips, slightly damaged, also can pass on self into the system, when the operation can be some big software throughput will restart or crash. Solution: replace memory. (3) memory of CAS value too small can also lead to instability caused by system memory, automatic restart. General had better use the default Settings, don't roll change yourself. 4.The CPU temperature exorbitant or the cache damage (1) the CPU temperature exorbitant often causes protective automatic restart. The basic reason of high temperature is due to poor cooling chassis, CPU, the CPU is undesirable reasons: the heat radiator thermal conductivity low, radiator material with a foreign body between CPU interface (1) for quality assurance, fan speed is low, the fan and radiator dust too much, etc. And P2, P3 motherboard CPU temperature probe damaged under the mp4 or within the CPU temperature detection circuit on the mainboard damage, the BIOS BUG in a special conditions of temperature, the CPU CMOS setup to protect low temperature, etc. Can also cause protective restart. (2) of an internal CPU, level 2 cache damage is CPU common fault. The extent of damage, or can start, when running into the system, the software (some throughput big media player, games, 3D graphic) will restart or crash. Solution: in the CMOS setup of shield (L2) or level 2 cache cache (L1), 1 or replace the CPU. 4.AGP display, PCI CARDS (nics), cat restart automatically (1) the external card or poor quality work not standard, AGP/PCI bus signal misoperation cause system RESET to restart. (2) and graphics, loose network system may cause restart. 5.Parallel, USB access is serial, fault or the incompatibility of external devices restart automatically (1) the fault or not compatible with the parallel damage, such as printer, a foot of short-circuit, USB equipment damage of short circuit, signal level sutural definition, opaque, etc. (2) hot swaps external devices, shaking, cause signals or power instant short-circuit. 6.Mainboard failure In case of automatic restart motherboard is rare. Generally RESET circuit are associated with a fault, Socket weld is empty, slots, contact undesirable, Individual chip, capacitance elements such as damage.