|It could possibly have over heated. If it's working since you received this reply, then that was most likely the case. And in that case, you may want to try prevent it from doing so again.|
If it still doesn't turn on, check the power cables. Sometimes you get a really bad power connector. It would be better if you give us some PC specs / model etc.
Also, is there a reason for posting this under Viruses? If you didn't know where to put it then that's fine, but if something happened before to make you believe its a virus let us know. That way we have better chance fixing it.
PEBMAC - The biggest cause of Computing problems.
Usually caused when the user accidentally causes the ID10T Error.