Laptop

Do you own a laptop computer? We have had one for a few years now. It was recently broken down for a while and we had to have it worked on. It was missed greatly. We tend to use it daily. Well, now it is beginning to shut down by itself after a short while. It is like it over heats and then just shuts off. My husband has actually set it on the air conditioning vent to cool it off. I'm not sure why it is acting this way. I do enjoy a laptop, but they don't seem to last very long. Give them about a three year life span.