My computer is a desktop HP Pavilion with Windows Vista (64-bit). When I turn the computer on the light that says is on goes on and the computer makes noises like is working but nothing happens, it's like the computer is off. That happened for a week then it really went on and I was able to use it like nothing happened. A week later the same thing happened, I wasn't able to used it for a week. Then a week later again I was able used it, and is been happening that for a month now. I ran my anti-virus but it didn't find anything. Can somebody help me!