Problem with keyboard

Hi! for 1 week I had problems with blender, is with the keyboard:

  1. when start blender all right.
    2)After 1 minute, the problem is with alt + numeric keys, for example, i press alt + 0 for a “=” but get an invalid character.
    or a press alt + 9 for a “)” but get an “?”

I not use laptop, this problem is new for my.

Sorry english :smiley: HELP ME!