I bought this laptop new a few years ago and have never had a problem other than replacing the keyboard pad due to a sticking space bar last year. Just today, the row of keys at the top stopped working (S1, Vol, Play buttons, etc. and AV MODE). I tried a reboot and they are still dead. Is this a hardware issue or something I can fix with a system restore, etc.? I hate to have to restore the system to default but I need the volume keys to work and don't know what I should do. Thanks for any help!