Purchased a brand new Toshiba X40. Straight out of the box the right hand shift key on the laptop keyboard would not work. Only the left key will capitalise words. We first thought that it might be the keyboard settings in Windows - the region, language etc etc but we have changed this to several different settings and each time it makes no difference. When we plug in an external Microsoft keyboard the right shift key works fine. How do we restore this key to working order?