I bought an Acer 5742z computer - being told it was a good computer. I would never again buy this junk. Within one year, the keys started to crack and fall apart. I have taken it back to the shop I purchased it from - and was told they had to send it back to the shop.
I would be without a computer for a month or more ( no guarantee on the time frame) . As I only have one computer and there is no loaner program with Acer, I cannot do this.
I now type without the letters on the keyboard. There is only one very small plastic knob upon which the letter rests. Thus, it is very easy for the key to crack if you do not depress the key precisely in the middle. Acer has made a product that can easily break with use and offers no way to get it fixed without returning it to the company for extended periods of time. This product is not worth the money if you have to have a back-up when it fails. Buy another brand of laptop.