Overheating and shutting down

Question

My Acer Aspire 5610-2328 notebook has been over-heating and shutting down since I purchased it around 15 mos ago. I sent it in to their repair center once and they turned it on and left it in the back room without any kind of load on it and told me that they couldn't find anything wrong with it. It has continued shutting down and now it says that my Windows Live OneCare that I purchased some months ago has quit working. It is freezing up and most of my programs are not responding on a regular basis. One of the biggest problems is that the date is stuck at June, 2005 and it won't let me change the date and time.