My computer has begun turning itself off for no reason Why?

I will be in the middle of typing a letter or document and it just shuts off. I have scanned for viruses, spyware, adware, etc there are none. i have done cleanup and repair. and it still is happening. and when it shuts down i loose everything i was working on at the time. the battery is still good. so help. how do i fix this?

My computer has begun turning itself off for no reason Why?internet security software

There may be many reasons for this problem. I can give you a link that deals with hard drive problems. Some RAM/hard drive problems can be easily fixed yourself by using easily available tools. I found the info at http://fixit.in useful

My computer has begun turning itself off for no reason Why?moto guzzi

is many reason for that first is the virus and you said u did check if its not check it when is shouting down if you see the blue screen before that its mean your system have kernel problem and its a memory but is not easy to tell you what is the cause of that its to many reason could be mother board or ram or other thing and its more common is if you add any drive recently and its happened after that is the power supply check your power supply and make sure you have more than350W .

good luck
My laptop also does the same thing, usually it is because it is overheating.