Laptop intermittently turns off

Question

I have a acer laptop and it intermittently turns itself off. It sometimes takes a few minutes before it will restart again and it will be fine until it happens again sometimes a couple of days later, or on other occassions it has happened 6 times in a row. Yesterday it started playing up first thing in the morning, it reoccured approx 6 times and then I turned the wireless off restarted and it was ok for the rest of the day even when I turned the wireless back on. It is really frustrating because it normally shuts down when you are in the middle of writing a document or writing an e mail. It turns itself off as though it has lost power but when we manage to restart it no errors come up to give any indication of what has happened.